
Things happen IRL while we are onsite.. also, we trigger each other sometimes, without intent. Sometimes it's even something the one being upset had no clue about previously. It's part and parcel of online therapy/support like we give each other here.
And... in a social chat, we can - or even try to - let "our guard down"... resulting in mixed feelings.
If you PM'd them, and it wasn't intentional, then you've done what you can. Learning to better phrase things... or learning new boundaries.... is also part of the social aspect of this site. But then, we are each responsible for our own actions/reactions. Hopefully, we do the best we can.
I think the other member was "kind" in one sense, to let you know. It might have been too much for them to tell you in the chat. Often the reaction is to just leave chat (maybe after making a strking blow back?) It's best if we find ourselves doing that, to go back to chat and try to work through it IMO.
I'm sorry to hear you are both suffering from this, and hope it can be a stepping stone for more healing.. which we all need! TC