Reply #3: This actually happened a few election cycles ago

[Yupster]

It was a senate race somewhere out west.

A Republican group attacked the Democratic candidate for being against some bill. Turns out the Republican voted against the bill too.

The Republican called for the group to pull the ad, but they said it would be illegal and kept the run that they had paid for before quietly going away.

Wish I remembered the race, but it was a little story about eight years ago.