Yeah if they were smart him and Erynn would watch it at least once just to see if there is something besides Erynn getting plowed they can notice that would be useful to them. Even if it makes them both uncomfortable and Erynn really emotional and brings back bad memories. Or at the very least ask Erynn if he can view it for this reason.
In the option where he got the phone the MC has done nothing with it, now a whole basketball game later... Ethan can report his phone as stolen and ask the phone company to block access to it.
Erynn just needs to tough it up a bit, after all the MC has already seen the video, it's not even the first time he will be seeing this.
Provide a shoulder to cry on later if necessary.
Devils advocate but wouldn't it be in the cloud. I am betting he most likely didn't use his phone to record it. Can you imagine yea Erynn take it you like it Don....ring ring ring what the fuck is that.
He did play us the recording from his phone, so at least there's a copy of it accessible by phone.
These days the first thing a phone demands for utilization is a login, if Ethan's login becomes invalidated(and reporting a stolen phone to your phone service provider is only natural), only a hacker will be able to access internal files of this phone.
It would be quite lucky to have the video in a memory card or the phone's HD.