I think some of the grammatical errors were purposefully done to make the texting more realistic. (Like typos or autocorrect) But I could be wrong just an assumption tbh.
I was referring to the interactions in some of the in-person and narration segments, actually. There was at least one line of dialogue I can remember off the top of my head where the word "simultaneously" is misused, and a few other parts with similar errors, and I think there were a few instances where some words were mistakenly repeated, too.