Your little squirrell is just getting tired, that's all.
I agree with Billy- no "damage." I, however, would conjecture that the high-pressure nature of the pump design isn't good to be wrapped up that high for long periods like autocrossing requires. Before I unloaded the Prelude I was looking for a method to alter assist, go manual, or cool the fluid better.
After some searching I found a cooler in Jegs or Summit that fit where the stock one goes and was finned (as well as increasing fluid capacity by a pint or so). I'd recommend something like this to any serious autocrosser. May not help the failure, but will help keep your fluid cooler and probably extend the life of the rack and pump.
FWIW: I had a major p/s failure in my '89, and NOT the high-pressure hose that everyone has blow. I had failure of one or more check valves in the rack. It evacuated the fluid from the system ALL OVER the engine and hood. Nasty.
The only cure I know of for the p/s prob is to take it easier. Steer smoother, try to stay at a constant RPM (that helped me a LOT) or simply bring the RPMs down (go slower).