I indeed think that invoking a 'discussion' what EO might do in Britain in absence of EOs is an attempt of marooning the case. And an example of prejudice against predators.
Can you find that one? Import of falconry birds is registered, so it would be easy to check whether any EO were imported. I think the scenario of a falconry EO imported from the Continent and released is highly unlikely, because EO is already relatively common and readily bred in the UK collections.
This statement came from an experienced representative connected to the BTO, and was similar in context to a quote from Dr. Mark Avery during his time at the RSPB..... maintaining a watching brief, so to speak. I hardly think either of these organisations have any corporate or personal prejudice against predators.