It wouldn’t be surprising at all if there are multiple mechanisms that differ in various subtle ways; but per NPR
“Bloomberg, which first located the filings, reports that “none of the filings lists the transactions as being part of 10b5-1 scheduled trading plans.””
I’m not an SEC whisperer, so I can’t be entirely sure whether or not we are talking about the same thing; but Bloomberg’s report was “these are specifically not trades made under the innnocent explanation”; and Equifax’ assertions have been “Oh, our CFO, US Information Solutions President, and Workforce Solutions President just didn’t know about the breach when they sold that stock”; which is the sort of…questionable…excuse that seems like something you wouldn’t resort to if you had a nice, solid, “Yes, the timing looks bad; but the paperwork planning out these trades was filed 18 months ago and is all on the up-and-up” explanation to point to.