Player 1 - Someone
I grant you the ownership of Macaboo III if you accept this peace treaty.
TURN PROCESSED
Player 2 - Me
Oh you mean the planet I just glassed? Na, I prefer something else.
TURN PROCESSED
Player 1 -
Very well, you drive a hard bargin, I offer you Macaboo Prime as trade for accepting this peace treaty.
TURN PROCESSED
Player 2 - Me
Well I would accept say for the fact that Macaboo Prime is now devoid of life. Perhaps another planet, something not in the Macaboo system. Perhaps a homeworld class planet.
TURN PROCESSED
Player 1 -
We offer you the only homeworld planet we have, Tebo IV. Now will you accept this peace treaty?
TURN PROCESSED
Player 2 -
I accept.
Not exactly to scale on the turns, but you get the jist of it.

I think someone should have explained to him that you only get one homeworld planet on a 1 planet start.

That player is no longer in the game.