Are you going to tell me with a straight face you didn't tell them there was something wrong with them ("diagnose them")?
If your stated belief is real, then I'd encourage you to reflect on why you were willing to violate this principle, and why, after being challenged on it, you deflected.
TIt is common to dismiss someone discussing something they care about, on the grounds that they care about it; they created this account to talk about Musk, so we shouldn't be surprised that's what they're doing. They related something painful, so we shouldn't be surprised it upset them. None of this should be held against them or discredit them.
If you were in there shoes, and assuming everything they said was true - is there really a different way that you would have expressed it?