It is well known in UK HR circles that the filing of "minor" grievances is encouraged by certain unions. This is done to tie up management's time, to continue the "hard done by worker"/ victim mentality of the employee and to allow the union reps to go to "meetings" all day long - rather than actually do the job that they were employed for by the company.
Spurious grievances are frequently filed by BA cabin crew. For example, a steward is told by the captain to take his feet off of the bulkhead - grievance filed against the captain. I foresee a complete re-write of the whole EG policy.