[James2001]

The cast might not have known, they might just have spliced the relevent ending onto the end of the dress rehearsal tape. As has been said, we know they filmed several endings- they showed some as part of the BBC3 aftershow, and I think some others got posted up on their website as well.

Similar to that, I remember with the "Who killed Tom King" story in Emmerdale, they filmed several scenes of different people pushing him out the window, and they showed them on Calendar earlier in the evening of the reveal episode, which made us think the reveal was going to be shown as a flashback. But then in the actual episode, all we got was Carl admitting to Matthew and Jimmy that he did it, there was no flashback (and Carl doing it alone wasn't one of the clips Calendar showed either), so filming all the alternate endings seemed bizarre when the reveal wasn't done as a flashback anyway.

And when it comes to the 2015 live episodes (or at least partly live for all but the last one), they had an #EELive hashtag on the live parts, and whenever I've seen them show a clip of those episodes, and when they repeated one of the during the covid break in 2020 and, is up on the iPlayer (www.bbc.co.uk  ), said hashtag has either been there, or the picture's been zoomed in to cut it off, which suggests it's the only version that exists- I would have assumed they'd have made hashtag-less versions for repeats and international sales, but it seems not.