Re: who had right away?
With all the above in mind huck, I probably would have held my course, dropped the engine and started it, and kept a close eye on the lobster boat until I could better determine what he was doing. Then if evasive action was needed taken it.
I think by changing course twice before you could actually determine whether he was laying his lines, or motoring out to a position to begin his set you were reacting to insufficient information.
These are your " local" waters so you should become familiar with your neighbors with whom you share them and understand how they use them. It's best that you not engage in arguments on the radio over who did what to who, lest you become a target. If they are docked 1000 ft from you, it might be worthwhile getting to know each other face to face.
Maybe start off by Letting them know that you tried to get out of their way, but weren't sure how best to do that...? See how it goes from there, keep it civil.... at least you'll each get a sense of who you are dealing with.