I think you need to remember Tommy Skipper is still learning.
http://www.advantageathletics.com/polev ... ipper.html Watching him vault, it did seem as if he was leaning on the pole a little coming off the ground. That may be because he may be over-gripping a little too much (holding too high). Later in Tommy's vault he doesn't line up well with the pole. What he does down at the bottom may be affecting this. Look at the Bubka sequence.
http://www.advantageathletics.com/polevault/bubka.html We all think Tommy is fast, but I believe when he learns to keep his hips under him better in the run and take off his speed will improve even more.
This may be of help from Vitaly Petrov:
"The question of where on shold take-off - before, after or on the vertical - should not be a matter for discussion, in so far as the vaulter can raise the pole to the maximum above the track only standing on the vertical beneath the grip. We have one more test for checking the grip of the competition pole. The vaulter stands on the vertical, holds the pole in the competitive grip where the pole is touching the back wall of the box. Marking on the track the point of take-off, he puts the pole on the track and places his right hand on the pole at the point of take-off; if he runs from six steps (thr run-up should start from a standing position) and makes the vertical position in the direction fo the landing area, his grip may be considered optimum for him, but if he does not reach the vertical or may take a higher grip and pass through, then he has selected his grip wrongly."