He also says that he wrote them something along the lines "whatever, let's do the first deal you have offered me" and then intentionally never read the contract. Who knows what they have discussed and agreed to "as friends".
The entire situation is very messy. Mojang fucked up by failing to get the contract signed and failing to even notice it. OTOH the writer seems like a contractor from hell who you wouldn't ever want to deal with, and that's based on his side of the story.