Re: Give way when hoisting the main?
It sounds like you were in a crossing situation. If you were "under power" transmission engaged. Then you were also a power driven vessel. "Technically" you should have abandoned the mainsail and maneuvered to allow him to cross. In ample time.
If your engine was on but the transmission was not engaged " not in use" Then technically you are a sailboat, he is a powerboat and he should have given way.
So were you underway...making way.. with the engine? at the same time you were trying to raise the sail ?
I agree, he should have given you the courtesy of falling off, but I also think at the point of the jam, you needed to put the transmission in neutral.