Hm, I think the problem with this comparison is that the measurements of what the EM drive appeared to be doing were very small, so much so that they were within the margin of observational error.
A macroscopic object that does visually clearly observable impossible maneuvers, which are independently confirmed by radar, which is only one of many such incidents, that really makes any probabilistic argument based on incredulity hard to accept.
Credible accounts, sometimes supported even by photos, videos, radar readings, or physical evidence, stretch all the way back to Roswell, and that's just the modern, better documented part of the long history of such accounts.
Like Richard Dolan says, the Occam's razor can also cut the way of the UFO hypothesis, when the evidence points to that more easily than to any conventional hypothesis.
Also, at this point, I'm not sure what could possibly be enough proof to at least start considering the option seriously, short of alien motherships starting to blow up landmarks. And even then, the first couple would undoubtedly be attributed to meteorite impacts and freak storms.
Fuzzy photos and videos that are in any way open to interpretation are obviously not enough, clear photos and videos are undoubtedly fakes and hoaxes, top gun pilots and astronauts apparently don't know what they're talking about, recovered materials are never alien enough, weird humanoid corpses submitted for autopsy always must be just human mutants, and no declassified documents or whistleblowers can ever be trusted.
All of that, and much more, forms a pile of (summarily dismissed) evidence that has been presented until now, on top of which the recent army videos sit, like the proverbial tip of the iceberg.
Treating every UFO incident as if it occurred in isolation, ignoring the trend over time toward it being more and more confirmed by more people in a more official way, and ignoring all of the testimonies credible enough for a court of law is how much mental gymnastics is required to still be content with doubting the phenomenon on parsimony alone.