That's what he may have done, but the "executive" in the title means he was an officer with authority to actually do stuff on behalf of the company. Unlike non-executive chairmen, whose power generally is limited to hiring and firing the CEO.

The board are often paid, but typically not much. Perhaps pro-rata "market rate" for the sorts of people on boards like this, but with the amount of time being so limited it's not huge sums of money. I'd expect much less than a typical SWE salary, perhaps an order of magnitude. I think the roles are often fulfilled for free.

In this case, it was the founder, so his upside is huge already from stock. Call that pay if you like, but I think it's a bit different.

He staged a coup to get rid of the CEO and reinstate himself so I'm afraid "he was just collecting a bag" can't accurately describe his role on the board. The overall point here being that of course he was aware they would be hiring, and even if he wasn't, it was his job to be aware. But on his first day the guy doesn't even have it in him to write the trite line of "this is wholly my responsibility".