How positions become marked as closed on ECN

Dear cTrader Support!

On an ECN account, is it possible for cTrader to mark a position as closed without confirmation from the LP?

I understand that cTrader provides millisecond accurate and detailed information on order/deal/position execution times and even gives a snapshot of the market depth at the time of the deal's closure.

Can cTrader display all this information about a closed deal if there was no actual feedback from the liquidity provider at the time?

I'm curious because of all the news surrounding the franc collapse about brokers revising/altering already closed (stopped out) positions many hours later, citing that there was no actual liquidity at the time. Can such an alteration legitimately happen to a position that was already marked as closed (with DOM snapshot, times, etc supplied) in cTrader on an ECN account?

Thank you if you can shed some light on this.