BA strike dilemma this Christmas

Owing to the threat of BA striking Christmas week I am seriously looking at booking a refundable ticket on Olympic to get us to Athens should we need it. Olympic Air is offering a fully refundable single for 206. My question centres on what BA's policy is if, due to strike action, we cannot fly outbound on BA as intended on 23/12 but still intend to use our return on 02/01?
I'm sure I read somewhere that you can't use the return if you have not showed up for the outbound? However surely if it's BA's fault that they can't honour the outbound then, provided no strike on the return, they should bring us home? Any thoughts would be appreciated.
Thanks
James
I'm sure I read somewhere that you can't use the return if you have not showed up for the outbound? However surely if it's BA's fault that they can't honour the outbound then, provided no strike on the return, they should bring us home? Any thoughts would be appreciated.
Thanks
James