Shin no Nakama janai to Yuusha no Party wo Oidasareta node, Henkyou de Slow Life suru Koto ni shimashita - Vol. 1 Ch. 1.3

[Axccel]

I don't know what's wrong with burning down part of the forest. Other than the contrived "this is the only place the herbs grow", in general destroying an acre of forest to eliminate a threat to the town isn't a huge cost.

Because doing so was entirely unnecessary, seeing as a formation of adventurers that, from what they said, was complete overkill for this job, and the implication was that it was actually an accident caused by their incompetence.