I highly doubt the BA aircraft "turned right" as we all know that's not a TCAS procedure.
It's not the procedure for an RA, however "When two aircraft are on a collision course, both shall alter heading to the right" is still enshrined in legislation.
As a happy result from an RA involves BOTH aircraft following their TCAS (And the DHL smash and JAL near miss both show this does not always happen) I would seriously consider a lateral manouvre if I believed it would aid in seperation. (Indeed, many manuals procedure for a TA invoke considering a lateral manouevre)