I agree that it was braindead, however, there is a great deal of deliberation involved. Any other form of "meeting" (to be grossly and dangerously euphemistic)

I agree that it was braindead, however, there is a great deal of deliberation involved. Any other form of "meeting" (to be grossly and dangerously euphemistic) would have involved lawyers and probably also consular assistance. A misuse (or, if you prefer, abuse) of anti-terror legislation is the only possible way to intimidate, interrogate and hold a foreign national who has not (and does not) currently commit a crime on British soil. "Stopping and detaining" was exactly the one option British authorities could not use, because that would have put him outside the law-free zone that is the airport. That's why they chose another way, and that's why they get, perhaps unexpectedly, a great deal of backlash from this.