lotus - I think the SAS role for the plane (?) is more to do with rapid movement of personnel rather than stealthy movement of same!
If Big Eric says they're septics going for a potter, no reason for us to doubt him. Tangos aren't daft, they know the SAS will be on any potential hostage/combat scene quickly anyway.
I'd be surprised if this was SAS willy-waving. If it is, it's not really necessary.