I can only speculate that the call was deemed 'not an emergency', in-universe. There is some rationale for that.

The UK 999 system has a structure called Silent Solution for callers unable to speak, whether through disability or if trying to call secretly & must remain silent. If you know the system, for instance as an abused partner etc with 'prior', then you are supposed to press 55 to indicate you are using Silent Solution. However, even without 55, the 999 operator will in any case stay on the line for some time to try extract at least some information, asking the caller to signal any kind of response - tapping, coughing, one-word answers etc - anything to identify a true response.

In the absence of any response, then all they can do is attempt to identify by background noise an assessment of the situation.

There would be no noise indicative of a 'dangerous' situation, merely some background conversation, and no response at all from the barman, so it's entirely possible that even in realistic terms, as opposed to simply script convenience, that no follow-up would be done.

For script convenience, of course, it was just an amusing 'nick of time' before he managed to speak to the operator, and we can forget about it once the camera cuts away.

I can only speculate that the call was deemed 'not an emergency', in-universe. There is some rationale for that.

The UK 999 system has a structure called Silent Solution for callers unable to speak, whether through disability or if trying to call secretly & must remain silent. If you know the system, for instance as an abused partner etc with 'prior', then you are supposed to press 55 to indicate you are using Silent Solution. However, even without 55, the 999 operator will in any case stay on the line for some time to try extract at least some information, asking the caller to signal any kind of response - tapping, coughing, one-word answers etc - anything to identify a true response.

In the absence of any response, then all they can do is attempt to identify by background noise an assessment of the situation.

There would be no noise indicative of a 'dangerous' situation, merely some background conversation, and no response at all from the barman, so it's entirely possible that even in realistic terms, as opposed to simply script convenience, that no follow-up would be done.

For script convenience, of course, it was just an amusing 'nick of time' before he managed to speak to the operator, and we can forget about it once the camera cuts away.