Actually, the RLA has very little specificity. Most of the "rules" are embodied in case law (court decisions). That is why the judge only ruled specifically that ONE of the 3 issues in the ABX case constituted a "minor dispute". He was silent on the other 2 issues, because the company promised to fix them immediately. If the company had failed to do so, the ABX pilots MAY have been able to resume the strike, absent a further ruling.
I can only assume that by issuing the preliminary injunction, the judge was satisfied that those 2 issues were, in fact, fixed.