The Islamic Republic may be fracturing. Many could see the present crisis as danger and opportunity.

That might cause one faction to refuse to honor what another faction is doing. Or it could cause a faction to try to represent itself as in charge when they are/were not. Either would be easy to do, since the Supreme Leader is likely just a figurehead or medically incapacitated.

What if a pretender faction represented to the Pakistanis they had authorization to negotiate when they did not so that the Muslim world would accept that faction as in charge. If it worked they'd have pulled off a bloodless coup.

Or what if a renegade army faction hoped they could develop alliances in the military by ignoring a bona fide cease fire.

Either might cause what we've seen.