The pilots are expert in flying and no doubt in-the-moment aerial observation; but its not clear why we need to take their opinion as final and impartial in post-event video analysis.
At the end of the day, everyone is fallible -- and even the experts are sometimes surprised.
These reports can only be treated as best efforts to fit observed phenomena into an existing framework of (inherently limited) understanding. When the phenomenon is adequately oddball, you have to expect an increased level of misinterpretation. See also: doctors, scientists, infosec practitioners, ...
Clearly, this is adequate justification for collection of additional data, but it's not enough to draw conclusions from.
And the pilots say it's something they can't explain, and have never seen before, on the record. More than one account.
The problem is the writer dismisses all of this, and takes the explanation of people who saw only the video. How dismissive the writer is of other's lived experience and expertise in their own domain is what I have trouble with.