I'm willing to put money on the mixer being Chris Bevins.There's always at least three people in the recording booth at one time: the voice-actor recording their lines, the director directing the voice-actor, and the audio mixer recording those lines on an audio program (ProTools, for example). Other people can mingle in the recording booth as well, other voice-actors waiting for their turn or a screenwriter going over the script, anyone. So there's always a witness to something going on in the recording booth. I can't remember the mixer's name there, but he's on record stating he's a friend of Vic's, and he might've left Funimation when Vic got terminated, or he's kept his mouth shut, I don't recall if anything came out about him on that in the main thread.
Monica's lies keep unraveling before her beady eyes, and her freak-outs on social media are evident that she has lost control of her own narrative. Whether she knows about Ron's antics or not, she's fucked up hard and now has to pay the price, and it's a hefty one.