CNN is just saying stuff to say stuff. Sure, if the trial were an impartial one then it would be damaging for the key witness being shown to be unreliable via contradicting testimony and an openly stated motivation to do harm to the defendant. This isn't an impartial trial. As you've noted:
If this were an impartial trial over a real crime then Stormy wouldn't even have needed to testify. This is an effort to influence the upcoming election, and that is all it is. The DNC has weaponized the justice system so that questions over a form being filled out correctly, which wasn't even a NY State form, is the basis for a hooker having the biggest stage possible to generate compelling content showing the GOP candidate in a bad light.