There will always be some pull when sprinting because the foot touches down infront the com.
True, the touchdown occurs slightly ahead of COM, but don't forget about momentum…the COM will still be moving forward at touchdown…Proper sprint technique at touchdown involves the stabilzation of the COM over the touchdown foot (amortization phase, hopefully as short as possible) followed by the forceful extension of the hip via the hamstrings in order to project the COM "up and forward" to maintain the forward motion.
(note: my comment refers to maximum velocity, not acceleration)
I think it's a pushing action. I'm not too dogmatic on most stuff, but any cue about pulling or clawing is bad news IMHO…
😉