It's probably a 'glitch' in the order of carrying out actions in a turn. If he 'gave' you the planet and ordered it to launch fighters int he same turn (planning to give you ONLY the planet but not all the cargo contents) it might have transfered to you and then launched the fighters. Ask him if that's what he did. If so, I would call it a misunderstanding of how the game works rather than a glitch, myself.
