It was Alaska - who are a BA "partner" - which makes me suspect the agent was bending the rules when he was checking the cancellation of the Alaska flight - the bookings were separate, I was expecting to pay for an economy one way the next day at a ruinous price.
Even if it wasn't an epic rule bend, it was hugely welcome after the annoyance of the Alaska cancellation and helped me reschedule meetings/work on my return quickly