Well, as a long time hunter at EE, I can understand both sides to this issue.
As most of you already know, the extensive road system at EE makes it easy to cover lots of ground on a bike. And whenever I see someone on a bike, they aren't hunting with a dog. So there's always that potential for those with a dog and those without to come into conflict. I don't know what transpired between the OP and the hunter in the orange OHA hat. But here's what's happened to me on several occasions.
I was covering a section of ground, roads on 3 sides with my GSP. I spot a hunter on a bike riding on the road to my right. I can see that he's watching me and my dog. He rides out ahead of us and stops at the next intersection with a crossing road. He's just sitting there watching us as we work in the same direction. I recognize what he's doing, he's now on stand while we push thru the field. Two issues here...1) If a bird flushes, I can't shot towards him, 2) He's in a position to take advantage of any birds we do push or flush.
Me and my dog aren't out there working for someone else and I'm really annoyed at this persons tactic of waiting to see what we turn up. Again, I've had this happen several times. Really hate when people without a dog slide in parallel to me or post up out ahead. When this does happen, I bring the dog back and we sit and wait. Or, we hunt in another direction. But I realize what it is, and it can become competitive with other hunters. Really, people need to find their own birds.
To the OP, as long as your not waiting for someone else to flush birds or posting up ahead of other hunters, you should be fine. The other side is everyone knows that early morning birds are often very visible, often on or next to a road. So a bike hunter has a big advantage over someone walking. Can't complain about that. It's a unique hunt in a very unique setting and a person on a bike is making the most of what's there.
Good luck on your next trip and hopefully without any further encounters like that!