Not quite sure if this was being agressive or just dominent?

We were walking round the farm yesterday & I saw a man & his dog coming towards us. The man was on a bike & the dog, a GSD running along side off lead.
So I made Tilly sit & wait at the side in case she got in the way of the bike. As they approached the man (quite an old man - I'm talking 70's) shouts "It's ok he's friendly" & slowed down his bike. So I let Tilly go. Well this dog lept for her & Tilly went into submissive lay but he wouldn't let her go & was standing over her. She yelped,I think he may have trod on her - he didn't look happy but wasn't growling.
I said to the man "call him off he's scaring her"
It took a while for him to move & Tilly came running to me.
Friendly! I think not. I told another dog walker who knows him and says he always says that but the dog is not friendly & has pinned hers down before.

Nothing to do with dominance. I'd say his dog was probably not very well socialised and was fearful but Tilly did the right thing which probably prevented it from ending up in a fight.
Hope she recovers and give her a biccie from me.
Becky

Ollie sometimes does this to other dogs he tries to stop them getting past him I just step in and make him stand aside and let the other dog through its only certain dogs he does it too and after doing it once or twice and me stepping in stops doing it. He shows no aggression and doesn't pin them down either. I can at the moment move a bit quicker than a 70 year old so I think that helps. Only just mind.