Hmmmmm.... while, yes, it has been pasteurised and will be so again pasteurisation at those temperatures don't kill off Botulinum. Under normal circumstances it is rendered inactive at cooking temperatures so you don't need to worry. But in this instance, when the temperature dropped below the 54C mark it may have become active again and we don't know for how long. Sure, when the temp heads up to 54C it is once again rendered inactive but the toxins produced while the Botulinum bacteria were potentially having their little party are the problem. These toxins are deadly.
You'd be pretty much playing Russian roulette.