Assuming their reason for leaving is genuine -- concern for the team's safety and lack of proper security measures by your opponents -- then I'd say it's been thought through very well.
There are times to be exceedingly slow and deliberate, but if you are concerned that an opposing fanbase was able to get a gun into the stands and potentially gun down some of your players and coaches, I'd think "immediate pullout, figure out the schedule later" is as logical as you can be.
But again I'm not knowledgeable of the specifics here so if that situation was overblown and they are using it as a copout to bolt, then I retract my statement.