I think you could have rebuilt, it was just that you decided to wittingingly or not to do so right next to my base, which I took a dim view of. In fact, at the time I thought you were building some sort of big cannon to rape my base as Grimmeh was attacking from the other side, and assumed you had a big force somewhere else. I was too busy screaming and trying to hold off him to go looking for you.
Grimmeh informs me that he:
A: Clicks right mouse button on the add unit member button to keep an automated wave of them coming, instead of manually left clicking all the time.
B: Places rally point flags about so units go where he wants them upon production.
C: Creates waypoints so units are always on the move capturing places and shit.
Also he is just scary good. How can he get a dreadnought so quickly eh? EH? Maybe it should be a me and you vs him later, Mr Chris!