Cruz himself? No, he’s not that stupid.
Anything with an email trail? Again, no, he’s not that stupid.
But I absolutely refuse to believe that something so outrageous would go out without at least the tacit approval of someone in the Cruz campaign. It doesn’t take anything more than a “chance” meeting at a local fast food joint or a gas pump, and “hey, we’re going to use an old nude photo of the other guy’s wife” with “that’s interesting” as a response. Negative would be on the order of “that’d make my friend look pretty bad.”
Can any of it be proven? Not a chance - again, no one is that stupid, especially not after seeing what Hillary is going through.
But it is incredibly naive to believe that there is literally no contact between people working very hard and spending a LOT of money for the same incredibly valuable goal - VERY discreetly, by lower level (but trusted) people. You can choose to believe that, I simply don’t. This IS politics, and people are playing for KEEPS.
The PAC that sent out this add wouldn’t care what Cruz thought of it because it has no affiliation whatsoever with his campaign. It is strictly an establishment PAC that was set up to take Trump down - it would happily run pro Kasich adds in any state that it looked like Kasich had a good chance of winning.