A meticulous hitman unwittingly becomes a tool in a complex scheme of revenge by a woman he regards as nothing more than a one night stand.

Even if you can make this story work in the script, you'll need to rewrite the logline as it lacks logic: you end the sentence with the event that kicks off the story. Always try to tell your screen stories sequentially, whether it be the logline, synopsis or script.

So better to start: "After a one-night-stand, a meticulous hitman..."

Is 'meticulous' a strength or a weakness? He doesn't seem too meticulous as he's dropped the ball in this case. Why did he overlook this? It may come down to his REAL flaw, i.e. the one he needs to overcome. Perhaps he is perfect in his observation and planning - except with women...

Finally, I concur with Tony above about the character's passivity.

Yes -- I'd have to agree with the above -- the logline is just giving us his predicament (yet, still not specifically...) with no indication of what he does about it.

To harken back to a previous post, it reads to me that his inadvertent slaying of his boss (or big crime figure) is the inciting incident and his main action throughout the film is trying to uncover who set him up and why..? If so, I think you'll find that the logline almost writes itself. At the moment the protagonist is weak/ passive, as he just ..."unwittingly becomes a tool...' -- you need to be specific in regards to the event that sets him off course, and then specific as to what he does to right that course...

Anyway, I'm intrigued, especially knowing this is a 'post completed screenplay' logline.

Good luck with it.

I dig this. You could either go Noir or Action with it. It has a lot of potential...

I think you need to make the protagonist more active. I read your original logline, as well as your revision. The revised one is better because you're focused on ONE event, but you still haven't really given your protagonist an action. It seems like he's going to be reacting rather than taking action. I realize that's probably not what you have planned, but that's kind of what the logline suggests.

I think you're on the right track though. Good luck with this!