SpoilerShow
destroying a bush so that you can throw/fire something onto a tile behind it.
I have a similar issue when firing bolt spells against enemies that are advancing towards me (sometimes the bolt harmlessly dissipates against them, not even doing "0" damage but just showing no numbers at all). I assume this has to do with them leaving a square just as my bolt enters it and essentially walking through it, much like how I can walk along a line of spikes without taking damage if I time it properly, but I assume that's a trickier bug to nail down, whereas fixing one bush would presumably be easy?