Litebulbs
there is a well publicised sickness policy which caused industrial "difficulties" when it was introduced about 6 years ago.
It is well known that it was specifically designed to reduce pattern sickness on 2 fronts.
To reduce sickness amongst BA cabin crew during obvious times (like school holidays, Ascot , Wimbledon etc) , and to stop crew doing the mass "sick-out" in lieu of a strike , which is what has happened in the past.
Furthermore crew were repeatedly warned that sickness during industrial action would require documentary evidence. BA doctors were on hand to offer free medical advice and certificates earlier this year during the strikes.
If anyone went sick during the strikes they would have been very aware of the risks they were running. Even the Bassa massive were very vocal about discouraging colleagues from going sick; even if only to boost their direct support.