I usually get about 80,000 out of a set of Bilsteins, but I drive very carefully.

You said you hit a pothole.... It is possible you splashed up some oil or whatever that had settled in the pothole and then it settled on your suspension pieces? Then, when the car was parked, it all drained off in one spot?

It would have drained off one drop at a time which you would never notice on the street since you would cover so much distance between drops. However, when the car was parked and the drops kept hitting the same spot.....

If you find no trouble during the bounce test, and it does not repeat when the car is parked again, then I would not worry about it.