There was still time and far too many bodies not safely on a ship. Pietro had been running people to safety with hurried assurances that anyone split up or waiting for family would find them soon, but only if they listened to him.
The violence and panic was beyond frustrating, people shooting people over televisions, robbing stores -- what good what it going to do any of them?
When he saw the people wrestling to keep hold of a young mutant he'd rushed to help without thinking, and was yanked alongside in the tail end of a teleportation.