The place that you had do your timing belt didn't do you justice if they didn't replace the crank seal to start with since this is a common problem with the earlier subaru's. I am a independent mechanic with my own shop. Last year I had a 97 Subaru 2.2 that had the belt jump 4 teeth and trashed the valves, so I know it can happen. It's not that common though. If a Subaru 2.2 or 2.5 breaks a belt going down the road, their is a 50/50 chance if you don't try to start it that no valve damage has been done.