So, it’s all the fault of the airline according to Manchester Airport. I made a complaint and their response is below:

”I was sorry to read of your experience as detailed in your correspondence. I can however advise that the disembarkation process and facilitation of passengers' entry in to the Terminal Building remains the sole are of responsibility of the airline - or their contracted Ground Handling Agent (GHA). For any concerns or complaints relating to this area, we would advise passengers to contact their airline directly.To offer some further clarification in respect of the present situation, due to a number of flights now having moved from Terminal 1 to Terminal 2 has led to a situations whereby domestic and Common Travel Area passengers are disembarking the same space. UK Border Force have therefore implemented the requirement for a security sweep of the area following alternating flights of domestic and CTA passengers. Though as previously advised the process for managing the transferring of passengers from the aircraft, and in to the terminal building remains within the airlines direct responsibility and area of operations. Therefore likewise as previously advised, whenever passengers experience any issues within this area, we would direct them to contact their airline, who remain responsible for investigating the matter - and if necessary the airline would I expect progress the complaint with any third party service provider as appropriate. Whilst we will continue to monitor the situation, and of course play an important role in a long term resolution, we are unable to assist in respect of this matter at this present moment.“