B. lapidarius is in no way impossible to tell apart from related species like
B. rupestrus (which, for example, lacks hairs on its corbicula). Furthermore,
lapidarius is very common and all its look-alikes are rare in the Netherlands.
@Ursus, if I were you I would check the shag and treecreeper, as the species you note are quite rare in the Netherlands, and they both have very common look-alikes. The alderfly is a very difficult one, as one needs to check either the heads of larvae or the genitalia of males to be absolutely certain. However, the past 15 years or so only
S. lutaria has been confirmed in the Netherlands to the best of my knowledge.