I would be more inclined to suspect an issue with the device doing the playback rather than circuits.
I would second this thought.
For major shows such as The X Factor ITV insist on having more than 2 fully redundant paths to playout, of which satellite would have been one of the backups, and I've no doubt playout would have switched between them before resigning to putting a caption up.
Therefore the issue must have been on all the feeds, which points to an issue at the video server or somewhere between the server and the encoders, playing the show.
You would expect the latter to be redundant (especially after a previous failure involving this show) but perhaps not the former if its been a late edit and the hasn't been time to arrange a safety copy (or whatever the digital equivalent is).
Given the late recording and tight turnaround, it's likely that full redundancy hadn't been setup at LH2. In fact it's quite possible that the show was played through the gallery from the server that did the recording. If they had time to transfer it anywhere else, they would have probably transferred it to Red Bee and have them handle it.
The fault cleared after a commercial break so presumably they were able to re-establish the circuit or switch to a reserve whilst off air?
For this circumstance it probably would have been better to pull if off air and re-establish the circuit given that what ensued was cancellation of a vote and replanning of the whole Sunday show. But as you say not a decision for Red Bee that.
It would appear that during the break an engineer fixed the fault (or rebooted everything, which quite often fixes minor faults).
The big complication with stopping the show out of a break is coordinating automation timings with all the external playout centres (Leeds, STV and Virgin Media Ireland). As it has been prerecorded, the ad times had probably already been agreed and put in to automation at all the sites. All you need is one not to be changed correctly and you get an ad break at just the wrong time. Therefore, given that the programme was still mostly watchable, stopping and restarting was probably considered more of a risk than letting it run.