You sound like you're arguing with me, but all of the rules you described seem to suggest that what the strikers did in this case was legal. They didn't blow up anything or steal anything, they quit working at an inconvenient time.
Also, I think you're imagining a set of gentlemanly Marquis of Queensbury rules around strikes that don't exist. This isn't an elaborate ritual like the filibuster; labor dispute precedents are written in blood.