It was more a general
when something went “phutt”, fairly big time..I heard it was more than just guard lights/stopbars but even if it was just that given the quality of some of the readbacks you hear and the frequency of traffic crossing 09R to get to/from T4 I could perhaps understand ATCs reluctance to continue to operate at full flow rate
if indeed that was the only issue.
Anyhow Inbound flights either held on the ground, some if not all of those already inbound to LHR were warned that they needed to prepare to divert, departures from LHR held.