For all we know, it could have been the product of opposition research done by her opponent, who has declined to comment on this affair.
Interesting that this relatively minor event has become nation headlines, too. It has garnered an inordinate amount of attention.
Dems, on the other hand, have no such worries, because their fellow travelers, be they politicians, supporters, "news" reporters, et al can be pretty much guaranteed to give them a free pass.