Eyaless
It is sad to see this level of childish action towards your wife.
If anything like that happens again make sure she either gets a name or tries to reciprocate by getting a phone picture of the said individual. As has already been posted on this forum BA managers are very interested in this sort of action as it is quite clearly harassment and may lead to bullying at a later date - either way BA have demonstrated that they have both the will and the tools to deal with such action.
Remember these people will hope to return to work with BA in the future - an oft repeated refrain is how much they love their jobs and working for BA. This could be true but if they love working for BA they should prove it by not breaking the EG about Bullying in the workplace. BA I am sure would like to be able to dismiss such militant fools and if the fools give them cause, let BA fight your battles.
It is easy for these idiots to be brave in front of a bunch of yahoo mates, but bravery implies a knowledge of the potential consequences of your actions. If they take these actions let them suffer the consequences. It is after all what they are prepared for if they have thought any of this through.
Tell your wife to hold her head up high and to record any texts or emails sent to her or any on-board bullying in the future. Let's make BA a place we ALL want to work without fear of bullying from our so called colleagues.