Seriously?! [the prospect of fire and potentially greater meals for his houseguests and anyone else that may need it also trumps his uneasy feelings towards the man in red. over the time that he'd come to know and face him, one thing was always a certainty with Archer. he was honest. whether he told the full truth or not, he wasn't a liar either. which meant that even if there was more to this than he was letting on...he could at least trust what was told by him. he'd ask how he found out later, or thank whoever did discover the use of fire away from the tree] I guess it makes sense... If the tree has something like a bounded field around it that repels fire, no wonder Tohsaka couldn't do anything. [it was the best that he could do as her apprentice to rationalize the situation]