"Rolled to a stop" and "crunched to a stop" is a question of semantics and P.R. - but:
- it means the aircraft still retained at least 20% of its touchdown (ground) speed when it ran out of runway.
- "less that about 30 knots" equates to "less than about 35 mph" or "less than about 55 kph."
Not exactly slow.
The NTSB does report on EMAS overruns (cf. Mike Pence/737/LGA and the incident at Yeager/Charleston, WV), so I imagine we'll get good information on the critical possible little details that make the difference - extra speed for gusts, reverser lever jam, failed deployment of spoilers, reverted-rubber planing, etc.