Any sort of aircraft emergency near the runway would close the runway. The tower doesn't know if they are going to blow the doors...panicked pax running onto the active and getting sucked into other airplanes engines is no bueno.

Sounds like they went off the edge of the HS, and maybe were still in the safety area.

I have no idea what the conditions were, but decent braking in the center of a contaminated runway can become poor braking as you get near the edges. If it's a contaminated runway, slow to a crawl before you test your cornering ability...