Big hands don't necessarily mean strong hands, but it's definitely a good start. There's plenty to be wary of with this troll, starting with the hands

"There's a good man. Or grasshopper, or whatever it is you consider yourselves."

Bert backs away a few steps, but doesn't want to be the first one to walk away either. Eventually they may put enough distance between them to safely be able to leave without fear of retribution.