TS, dude sounds like he was a jerk.
I usually walk my GSD off lead, and will occasionally let Troy off lead, but usually only if we are deep in the woods somewhere where no one is around.
As with a lot of things, a few people (like the one TS is talking about) kinda ruin it for everyone. If the owner has it under control, I'm fine with others walking their dogs off lead. It's the poorly behaved dogs that irk the hell out of me.
TBH, one of the reasons I walk Bail off lead (in addition to reducing the number of leads) is so she can handle this type of nonsense. Unfortunately, she's had to do it a few times.