It could be. Or maybe it hired extra staff with anticipation of the new cotract and would reduce to the regular size and crew. What if without the disiplinary action others think they could do the same thing and more people decided to just walk out when they felt like it?
@Smtwn829: Arguably, if they all walked out, no workforce on that day. If you fired all of them, no workforce, period, until you hired and trained others. So how would your business be helped ?
I am not saying that I would be against rehiring them if they reapplied. You do bring up a good point. It would set a company back significantly. Either offering to hire them back or finding other qualified workers that would not require the train seems like the best option.