Nice spoiler warning there gopher-nuts. Seriosly, is it that freaking hard to take 5 extra seconds to add in (spoilers)? I've beaten it twice now so no loss for me, however some people have not so why ruin it for them just because your being lazy?
And to help you out. Just try to time the transfer better. Or move to boat away from the chopper, wait for the shot, then hop on as he reloads.