I don’t think Trump should have fallen for that mischaracterization of Heidi Cruz. She is actually a lovely lady and the long days on the campaign can wear on one’s appearance. Plus, there is Photo Shop to exaggerate things if needed.
However, Trump probably used the comparison image because it was handy and he did not want to spill the real beans yet, which he has as his Ace card.
Yes, maybe he should have taken the high road..but doing that in life doesn’t get a person to where he is. It’s just not his behavior not to deal with something like this head on.