I don't remember having seen so many "twists" in a film since I saw the two comedy-thrillers: Joseph L. Mankiewicz' s Sleuth (1972), based on a play by Anthony Shaffer, and Sidney Lumet's Deathtrap (1982), based on a play by Ira Levin. Both films (as well as this short) involve the triangle: husband - wife - lover (though the wife never appears on screen in Sleuth).
Based on a comic strip titled "Imbroglio" (i.e. complicated situation) The Bloody Olive has a distinct theatrical ring due to its strict observance of the unities of time, place, and action.
On the other hand the film reminded me of the old black and white Alfred Hitchcock tv series, in which two key ingredients were suspense and comic relief. But an even more important ingredient was, as Robert E. Kapsis writes in his book Hitchcock. The Making of a Reputation, the "reliance on the short-story formula of a simple tale which 'builds to a surprise turn or twist at the end'". In a letter to a European researcher, hired to find useful stories - a letter written in February 1955, seven months before the series premiered - Hitchcock stressed "one important factor (...) and that is that the ending should have a "twist" almost to the point of a shock in either the last line or the last situation."
The Bloody Olive consists of an accumulation or rather a compilation of twists, its raison d'être being an intertextuality which also includes visual elements from horror and especially film noir.
When the film opens, we see a box, nicely decorated; it looks like a present. Hands open the box, which contains 12 glass globes - Christmas tree decorations, while the music (a kind of Fats Waller swing music number) implies that we are going to see a metafilm, because the lyrics are: "Let's go to the movies - and see a lovely show." And we certainly do.
The broken glass globe and the kitchen knife, which is stuck into an apple, might be omens of something sinister in the life of the nice couple with the sugary smiles - the glossy surface may not be absolutely perfect. And just as they are about to seal their happiness with a kiss, they are interrupted (a reference to Touch of Evil?) by the door bell.
Now follow 10 murders - or rather attempts, plus one confession of murder, which is the denouement of the plot, all committed with guns, daggers and knives, threats, and poison - and evenly distributed among all three characters: Werner, Mylène, and Sam. (12 glass globes minus one broken equals 11; is the box a presentational omen?)
Furthermore there are 17-18 twists or surprises.
Thematically the matrimonial triangle refers to many combinations especially in films noirs and to various femme fatale-types.
Visually the film seems to be an illustration of J. A. Place & L. S. Peterson's classic article from 1974 "Some Visual Motifs of Film Noir."
Many of the shots are lit in low-key, with hard chiaroscuro lighting on especially Sam's face (but then of course, he turns out to be the real murderer). A good example is the first murder of Mylène, where Sam threatening her with the dagger corners her, and she dies from a heart attack; the many heavy vertical lines on the wallpaper or curtains, forming a prison-like background, underline her entrapment, and throughout most of the scene the camera is placed in such a position that several times it looks as if Sam really stabs Mylène with the dagger, though the distance between them is several meters (cf. Welles' putting on his gloves in order to strangle Tamiroff in Touch of Evil).
Another example of chiaroscuro lighting, almost overdone, is the shot in which Sam puts down the poison on the table; the small bottle in focus is partly clearly lit, partly in the dark, whereas the background with Werner is blurred - as if to anticipate Werner's blurred vision and black-out a few seconds later; several of these shots of Werner's black-out are filmed with a subjective camera, unfocused and in oblique angles (perhaps a reference to The Lady in the Lake and the first half of Dark Passage?).
The next shot is rather unusual: a perpendicular high angle shot, which is the only one outside the credit sequence, where we see this kind of camera angle. It shows Werner lying dead on the kitchen floor - a black and white chequered floor, like a chess board (not a bad symbol for this game where the next move might make one or two of the characters checkmate).
Racking focus, which can be used instead of a cut, is used extremely well in the shot in which Mylène, who has just been hit in the stomach by Werner's dagger, suddenly drops down out of the frame revealing (by a very quick racking of the focus) Sam sitting on a chair in the background and thanking Werner for getting rid of his wife.
The last and most impressive visual (and sound) element I will mention is the so-called "bus"- effect. In his book Val Lewton. The Reality of Terror, Joel E. Siegel explains it like this: "Lewton particularly enjoyed devising moments in his films which would cause audiences to gasp with terror. His name for these moments of sudden shock was "busses". The term derives from the Central Park sequence of Cat People (1942). Jane Randolph, crossing the park late at night, hears footsteps following her. She stops under a street lamp and looks back into the darkness. The noises stop; she sees nothing. As soon as she walks beyond the circumference of the lamplight, the footsteps begin again, and she hurries to the next lamp-post. At the moment when the audience tension is at its height, a bus
coasts into frame, simultaneously applying its pneumatic brakes in order to let off passengers. The unexpected appearance of the bus, sight and sound interrupting an already tense scene, invariably lifted the audiences several inches out of their seats".
Two good examples are the scene in which Mylène has just shot Sam, and Werner suddenly flicks on the light (the music score underlining the shock effect), and the scene in which Sam reveals himself as the murderer, and Mylène suddenly (without any music) emerges from the bottom of the frame saying that the game is over.
The police pop out of the mirror, breaking Sam's illusion of a private party - and likewise, the policeman in charge, in an ironic metafilmic break of illusion (the fourth wall), warns us, the audience, about driving safely and wishes us a Merry Christmas.
Luckily the film ends (traditional Hollywood happy end-music), and the last surprise: an old-fashioned iris-in closure (a popular silent film technique, often used by Griffith), before the twists become tedious (or the filmmakers ran out of variations). My great admiration is for the dedication of the Belgian police who spent Christmas Eve in hidden positions to be ready to arrest the culprit. I wonder how many days and hours Mylène and Werner spent practicing the masterplan and arranging fake plans with Sam. Perhaps you shouldn't ask questions like these, but instead invite your girlfriend to watch a new Belgian short film on video and "see a lovely show".
 Robert E. Kapsis, Hitchcock. The Making of a Reputation (Chicago, 1992), pp. 37 and 39.
 J. A. Place & L. S. Petersen, "Some Visual Motifs of Film Noir", Film Comment, Vol. 10, No. 1 (Jan-Feb 1974) pp. 30-35.
Joel E. Siegel, Val Lewton. The Reality of Terror (London 1972) p. 31.