See I'm thinking he was already degenerating and if they hadn't gotten the boys out of him he would have turned into a five year old. Tuvok would have thought of leaving the ship, he already had control access at his station to stuff. He would have set the ship into some kind of lockdown mode, grabbed a shuttle and fled, probably rigging up a cloaking device while he was at it. Tuvok's smarts and Neelix's desperation. But there was no action, only a speech. "I have the will to live of two men." A lot of good that did him.