Poirot. He may be called differently, but this is in fact Poirot; and I seem to recall that something close to this game's situation was used at one time in a Poirot book or movie... I might be mistaken, though. Perhaps this situation, where you are the detective who doesn't really know anything but just bluffs his way through the case and gets everyone to confess, is just so natural given the genre that one has the feeling that is must always already have been part of it.
Which brings me to my first pronouncement: Death off the Cuff gets very high points for situation. Very well done. Just the kind of situation you would want a good detective game to explore.
But is it a good detective game? Here I am less impressed. One proceeds by examining everything and talking about absolutely everything. Fair enough. But then some descriptions may change, and you need to examine everything again. And again. And again. And once more. And another time. This is boring. It is also really weird when we suddenly "see" things that should have been visible all the time. And don't think that you can spare yourself some time by making smart deduction, because you cannot: the new avenues that can be opened are in no way predictable, and indeed at the end you'll need to start investigating the single person you have the best reason not to suspect. And somehow, at that point you need to notice that he is wearing a uniform that is not the real uniform of Scotland Yard, which neither you nor anyone else noticed before, even though the guy has been standing there for who knows how long? (The player apparently also needs to know what a Scotland Yard uniform looks like. That, or just obsessively talk about everything.)
So, great situation, enjoyable development, but bad gameplay. This game would have been far more enjoyable if it had been a lot easier, with more in-your-face descriptions of changing details. Still -- it's worth playing. Just hit the hints soon and often.
P.S. One reviewer wrote that with some slight changes, Death off the Cuff would be in the same league as Make It Good. I disagree, but that's not because this game is bad. It's just that Make It Good is one of the best IF games I have played.