DM will have to decide when Tess speaks versus Angela's progress in her current trajectory

I have a few possible reactions in mind depending on when things go down. I'll let the DM know so he can include in his post.
As for everyone knowing and shouting out trigger words, I figure that if you didn't go back and find them in the Q&A, before you posted, then you may know them, but they didn't come to mind before you reacted. We are all human, after all

I like how Tess handled it, for the record...could simply come across as one of her quirky expressions Tess is fond of throwing around.
As for having been around long enough to know...I guess that is something we haven't determined who knows what besides Grace. I would hope that you wouldn't use the command to knock her out lightly as it would reveal those words in front of people we know not to trust, and having Angela wake up with no memory in front of strangers with guns may also not be fun for all.