The number of locks used is very volatile, a single process can accumulate and release a large number of locks in a short period of time. Once the 1204 is hit, the process rolls back and the locks are released, which can happen quite quickly, particularly if the locks are shared locks. What matters is not the conditions now, but what the conditions just before the 1204 was raised.
You can configure ASE to take a shared memory dump (CSMD) on the 1204 error. Then the next time this happens, the resulting dump can be looked at to see what used all the locks.