I've found that for most of the reactions done here, if you don't see a change (ie no heat released, no color change)... that is indicitive of no reaction taking place. Hg/Al, isomerization, peracids, gassing, etc, etc.. they all involve some sort of observable change in the reactants, if you're not seeing that, then no reaction has taken place. I'll agree with you that the opposite does not hold true (ie, just because you see a change, doesn't mean the reaction in question has taken place)
This boils down to:
1. if locrain's crude isosafrole was water white clear, like his starting safrole... that the isomerization was a failure.
2. if locrain did not observe something of a temperature increase and/or a color change from the peracetic, that the peracetic didn't work either.
(no offense intended to anyone! I don't intend to come off like a jerk on posts like this...)