The entire case raises a number of disturbing questions, the answers to which are vague at best:-
1/ How were the drones identified as such in the first place? - given that doubts are now expressed as to whether they were drones at all. Somebody must have first reported this - who was it, and precisely what evidence did they hold?
2/ Was any official daylight verification of the sightings made by police/intelligence/airport management, before the decision was made to completely shutdown the airport? If not, why not?
3/ Since the suspects concerned have now been released without charge and had cast iron alibis, exactly what evidence caused the police to arrest them in the first place?
Personally I'm left with the distinct impression that there was an almost hysterical, unthinking reaction to the initial sightings, then further knee jerk actions in arresting the suspects concerned. All part of the really worrying trend of downgrading the importance of actual evidence, and seemingly placing more reliance on "some bloke down the pub told me".
Even more concerning is that Paul Gait's employer contacted the police early on to verify that he was at work at the time, but nobody got back to him or seemingly followed up this piece of highly relevant information.