On March 31, 2014, HeyUGuys posted an interview with director Ted Kotcheff who talked about working with Sly on First Blood and a lot of other things. Here are some tidbits…
The received wisdom in Hollywood was that Stallone only worked as Rocky, so my decision to hire him wasn’t championed.
I sent the script to Sylvester regardless, and he called me the next day to say he loved the idea. I’ve never had such a quick and positive response from a star in my whole career in the business (laughs). He only had one request, and that was to do a rewrite on the script with me, to which I agreed. One of the biggest strengths Sylvester has is a great populist sense of what works. He knows what audiences like and dislike in a film.
…[an] idea he [Sly] had was to keep John Rambo silent throughout the film. Directors love extreme ideas like that (laughs).
We always considered Rambo to be on a suicide mission, which was how the original script ended. The moment he crosses that bridge he knows his outcome and it’s not going to end well, but he’s doesn’t care because as far as concerned – there isn’t a place left for him in American society anymore. The way it was written originally, [Colonel] Trautman was going to put an end to it all but instead hesitates, so Rambo grabs his weapon and pulls the trigger, blowing himself away. We shot that, which was brilliant, but Sylvester came over afterwards and said the audience would hate us for putting this character through everything only to have him killed at the very end.