Paper today said the crew had trouble getting the reverse thrust levers to move, they might have been distracted by this and if not using auto brake might have delayed the stopping process?
If the throttles are not fully closed the reverse levers will be hard to move and even jam until the throttles are properly closed. This has happened to me and others several times in the sim, but luckily not in the airplane.
In these circumstances any delay would be a bad thing.