Classic
I can't believe a BA aircraft diverted due to a Union dictat. The Captain is the one who makes those decisions,unless advised by Controlcentre Lhr of other problems.
I only had a problem once during a tech delay, of some of my cc advising me they wished to contact BASSA to see if they should continue. Although we were legal in FTLs . Two were reluctant to continue after contacting BASSA. I offloaded them after advising the CSD, and got on with the job, arriving at destination well within legal limits.