Not on my site but I have seen the occasional complaint here or elsewhere. Even if Adwords themselves are strict about classifications the ads could come from one of the "google certified networks". Looking at my account there appear to be 948 of those.
Presumably the whole system depends on the advertiser categorising their ad correctly.
This has been happening for quite some time. I have most of the "sensitive" categories blocked but some still seem to be cheating the system.
As a direct advertiser once warned me that they would pull their ads unless I stopped showing dating ads I take it pretty seriously. When I spot one, I just block the domain entirely. I do not see that many anymore.