I agree. Right or not, he should have avoided commenting on this. Trump has said several times this week that its up to the senate so he should be consistent and stick with that narrative, at least publicly. This just elevates her charges into the presidential realm and gives her more publicity. Bad move in my opinion.
They tried to commit a driveby in the dark of the night only to find the glare of public scrutiny focused on the whole thing and the depraved enclave of white privilege this woman grew up in. Publicity is exactly what this crowd is seeking to avoid.