Is it possible to alter the transition in progress?

I'd like to programmatically alter the target state of a transition in certain situations. I thought I might be able to do it with hook_workflow, op == transition pre, but the transition object isn't passed by reference.

If I veto the current transition and create a new one from within hook_workflow, I have to do something to prevent an infinite loop. I'm doing this whenever the current state is X.

Note that when I need to change the target state, it's always back to the previous state. Is it possible to use workflow_revert programmatically from within hook_workflow?

Thank you!