separation. A 10.5 guy leaves an 11.5 guy in the dust at that point. A 10.5 guy has no need to make an 11.5 guy "overrun" him...he just turns on the jets and leaves him behind.
It's funny you say that it looked like Blackmon wasn't "running all out". I've had that same impression every time I've watched him practice, scrimmage, or play. Compared to Trey Dye, or even Mitchell Jeurgens, Blackmon looks flat footed and slow. Until I see reason to believe otherwise, my expectations for Blackmon are very, very low.