The OUCON suite at the end of the corridor was an entirely separate operation to NC1 and 2 and could actually play programmes to both networks at the same time, which is why there were holding slides between programmes when one announcer was doing both. It was all U Matic tape based, so bypassed the television centre VTR department, and the announcers loaded the tapes and ran them to the network.
I am just guessing here, but presumably because the suite worked to both networks it couldn’t therefore genlock to either (and I’m also guessing that the synchs for the two networks were separate and not necessarily locked to the same master synch).
I have heard that each network control room had an OU Switch that put control of the network through to OUCON.
It’s also well known that while a non synch cut from source to source was relatively invisible on television sets, VCRs were far more upset by them, so surviving recordings subsequently uploaded to YouTube make these cuts look far more violent than they actually were.
As I didn't work at TVC
, I'm not 100% on this, but my understanding was that CAR generated the syncs used by everything, including both BBC 1 and BBC 2 network control.
In fact, as the next cog in the chain, our waveform monitor was locked to external syncs generated from Net 1. Net 2 locked to it exactly, so I am reasonably confident that was the case.
Next point north, Pebble Mill, also used to lock their SPG to the incoming Net 1 feed every morning, and would have used that for everything, and I can't imagine that any of the other studio centres with both networks going through them would have done anything different.