"...while his sights aren't on the target."
That's a tough claim to make with that photo. It seems possible to be the case, but.... we can't see the target. Additionally, USPSA rule 8.5 requires that the finger must be outside the trigger guard "Except when the competitor is actually aiming or shooting at targets..." Without knowing the exact target placement (unavailable in the photo) it's not possible to claim that the competitor isn't meeting that condition.
Further, if Todd G's assertion that the "sights aren't on target" is the cause for a DQ, then every Mike called should result in a DQ. Yea, I'm being a bit literal. Internet.