He lucked out. Which is the whole point. You don't hear about all the other people who got a small bonus and were kept on at roughly the same salary. It works out decent-to-great for founders, but employee #3-10 not so much.

Although I'd be interesting in knowing. Granted, most people probably consider a acqui-hire to Google or Facebook a great medium term career move.

When I read that in-context it seemed clear that the "us" in that sentence was Powerset. He said that at the time of the acquisition he wasn't even thinking about Boundary and he mentioned starting the company only in the next paragraph.