I believe if you state intent to hurt someone, or yourself, they have a duty to warn.

However, you did not state any intent to harm but said you wished X. Personally, I think that T was a bit extreme. Not only because there was no intent to harm, no plan... but you also don't even have a clue where your ex currently is.

It's up to you to go back to this T and make it clear that you did not threaten to do anything to that ex and see how they react and whether to stay with them. If it were me, I would not stay with them. I would not trust them and would feel I'd need to watch extremely carefully everything I said in case they jumped to the wrong conclusion(s) and 'punished' me.