On one hand - yeah. On the other - perfect evidence for the divorce case.
I mean, it's not like he deliberately set up a hidden camera to record her having sex. Just used an already available camera, that presumably she knew was there, since you usually buy that kind of stuff together.
Without this recording she says she didn't cheat, he cannot prove otherwise, and money and assets get split unfairly.
Not necessarily saying this is how the case should have went. It's just another angle to look at the situation from.