How Much More Quickly Would He Solve The Case If He Didn't Have To Worry About His Mustache?

I've been watching a lot Hercule Poirot mysteries lately, with David Suchet as Poirot.

I'd watch several of them in the past, but I did not remember Poirot being so quick to toot his own horn. On at least a couple of occasions, Poirot tells the murderer something to the effect of, "Your plan was almost perfect, but you did not count on Hercule Poirot!" Doesn't he know the murderer is supposed to say things like that? Scooby and the gang never said things like that; it was always Old Man Jensen who ran the amusement park that complained he'd have gotten away with it if not for those meddling kids and their dog. You make the villain admit you beat them, rather than do it yourself. It's more impressive, and it sounds less like boasting that way.

I should be used this, after all the epsidoes of Monk I watched, but the explanations Poirot comes up with for how the mruders were committed seem truly convoluted, and I sometimes wonder how he'd prove them if the accused didn't always conveniently break down and confess, or flip out and try to kill Hercule. Take Death on the Nile. Poirot's explanation is Simon faked being shot, convinced the witnesses to see his ex-fiancee (who had fired at him) and take her to her room, then took off his shoes, picked up the gun, ran to his wife's room, shot her, ran back, swapped out an empty shell for a fresh one (so it would appear the gun had only been fired twice), shot himself in the leg for real, wrapped the gun up and threw it out the window, all before anyone could return with a doctor. There were unexpected witnesses, they were killed, so and so forth.

It works as an explanation, but it seems hard to prove. I'm trying to find whether they knew how to test for gunshot residue on a person's hands in the 1930s (they may have had the paraffin test back then, I'm not sure). Even if they did, how much will that help? Yes, the ex-fiance would have the residue if she shot one of the witnesses as Poirot says. But the residue could also possibly be there from her shooting Simon in the leg, if it went as we were allowed to believe through most of the story. The answer may seem perectly obvious to Poirot, but they have to convince a jury of it.

Regardless, they are excellent explanations, and I'm suitably impressed with Poirot's deductive ability. I think what I like most about him is that in some of these cases, he gets a feeling a death is about to occur, and works to prevent it. He hasn't succeeded in any story I've seen so far, but it's a nice touch, to make him more than the guy who steps in after a murder and puts everything together. When I get irritated with how he treats people at times, I think uncharitably that he only cares about the case as a puzzle to solve. These moments, when he tries to dissuade someone from acting rashly, help counter that feeling.