Humans are much more complex than animals, so the roles we take, especially if we are intelligent humans, will change for many of us depending on the circumstances.

I am not normally dominant, but I can be dominant, very dominant in a working situation, if there is a need. Put me with a group of people who have a job to do and I see that no one is getting anything done then I take over immediately. I start odering everyone around, nicely, but still I get them moving and I get the job done.
But give me the chance to be a supervisor on a daily basis and I turn it down, immediately. I don't want to order people around on a daily basis.

Bully me and I cower. Bully my friend, a child, or someone weaker than you, and I'm all over you.

Sexually, I'm submissive and that's the most erotic play for me, but I can be very aggressive in vanilla sex and enjoy that too.

I'm sure I am not the only person who adjusts and takes on the role necessary at the time.

And back to the original thread. Kostly, the guy was a jerk. Being dominant had nothing to do with it. Treating people badly is not domination.

My son is an alpha male. Males immediately sense this and treat him accordingly. I have seen it happen over and over. He is huge, very strong, and carries himself with confidence. He is also very friendly, polite, and compassionate to all.