Yes, I imagine that's fairly common. Conversely, I've also stubbornly pushed through speech blocks to say something difficult, only to realise afterwards that I shouldn't have said it because it was the wrong thing to say, the other person wasn't listening or in tune with what I was saying, or I just hadn't thought it through. I swear sometimes the block is there for a good reason, or my brain uses the stutter to warn me that I should think about what I'm about to say before I start.