Step Timeout Behaviour - Help Required

In our process model, we have StepA with timeout set to 2 minutes. There is a timeout transition and an error transition associated with StepA. Whenever the flow service for StepA throws an exception, it takes the error transition and the process instance moves to completed state. However, after 2 minutes when the timer expires, something happens within PRT and the StepA moves to ‘Waiting’ state? Doesn’t the timer object get cancelled when a step throws an exception and takes error transition?

Please help.

Best Regards
Sivaraj Lenin