Lightbulbs,
I disagree. If an employer knows that that on specific occasions, be they social or industrial, that staff sickness levels rise far higher than the norm they are surely within their rights to demand a higher level of proof from their employees. In this case Blu Riband says BA supplied doctors at the workplace to sign off sickness.
Surely common sense says if you do get a cold on a strike day and you know that by reporting sick you will be classified as a striker you would go into work and see the Doc for free (no sick note cost) to ensure that you were not penalised. If you were so sick that you couldn't get into work i.e. car crash, then other documentation would be easy to come by.
Trust works both ways with regard to self certification. If the employees have continually shown themselves to be unworthy of that trust is it any surprise that the employer acts?
Regards