Also didn't notice a particular case here, but if all code passes up
until we get to the `foreach (var h in nestedHitObjects)` below, then we
could end up stuck here for quite a while.
Having these be separate implementations sounded awesome at the time,
but it only ever led to confusion. There's no practical difference if,
for example, catch sees hitobjects with `IHasPosition` instead of
`IHasXPosition`.