Hi Mike.
Hmmm.
That's interesting. The only "speculation" was not mine, but I did mention in the thread title that wake turbulence was suspected; this was derived from the quotes of an NTSB spokesperson in the article. While not a final NTSB report (which may be forthcoming a year or more from now), it seemed like more than just idle speculation.
I thought it may have been educational for the rest of us.
My mistake.