Did anyone manage to understand how many people Marty had killed in Point of no Return (airdate 18/03/09)

well, he did actually сказал(-а) a quantity.... but, time befor at the MI's office sid had a lot of bodies there......... i could say еще than 10....
i think there are much more....

From what I can tell from Sid's office, and what I could infer from the rest of the episode, I would say above fifteen and under 25.

I don't know how it sounds in english when marty sais how much because i saw it in german - I'm from austria - but in german it sounded like "ich weiß nicht." that means "I don't know" but, like i said, i don't know how it sounds in english.. But if it sounds Similar like "i don't know" that could be the reason why sid или hawkes, i can't remember who asked marty how much, looked So shocked when marty сказал(-а) whatever he said.. ;)