It depends on the context, if the state machine needs to roll-back for any reason then the answer is yes. A example would be Parser for an LALR (Look-Ahead/Left to Right) Grammar were it is essential. However if there are is no need for roll-back then the answer would be no.
In this case since you are modeling state machines you need to be able to handle both kinds, those with and without roll-back; other wise as he says your tool is useless.