I have to tell you, that's precisely what I saw.
4 seconds sound clip from the Platoon movie soundboard.
You can hear this line at 00:35:24 in the Blu-ray version of the movie.
Quote context
[...]
- I got to run. I'll catch you men later. Enjoy yourselves tonight.
- Well, that is one sorry-ass motherfucker.
- A guy like that make it? Yes or no?
- I have to tell you, that's precisely what I saw.
- People say I'm the life of the party 'cause I tell a joke or two.
[...]