Stretch was very sophisticated at manipulating people and was willing to invest a great deal of time into his schemes. When did Herc go bad - middle of September? I, along with a few others, received a July PM from Stretch (July was at the height of Hercs popularity). Stretch stated in that PM that he knew Hercules' gear had problems and he wanted advice on what he should do. That was TWO MONTHS before Herc turned scammer.
His PM was under the guise of him being concerned about his reputation taking a hit for backing Herc but that seems unlikely since his reputation was bulletproof at that time. Stretch had many good friends and followers on Meso but the members he PM'd for advice were those who weren't in his camp.
Why?
I believe Stretch was looking for cover for when Herc went down. By confessing his concerns about Herc to the members who weren't in the Stretch fan club well before the scam hit, he was hoping it would head-off any chance that those members would question his involvement latter.
What's important here is that after that PM, Stretch never acted on the advice he was given. In fact, he remained completely silent (in public, at least) on Herc's problems until the scam broke. However, as we latter found out, rather than distance himself from a source he knew was having problems, he moved even closer by supposedly supplying Herc with Bio gear.