According to the specs in the video;
Drift car Am Iron car
3200# 3600#
463hp 424hp
398tq 409tq

Yes, it appears the drift car is fully blocking the lane on occasion and you can hear the Am Iron car feathering the throttle to avoid hitting him. If they revesred the starting postion, I think you would see a much greaer delta in times across the stripe when the Am Iron car is not waiting for the Drifter the be clear of contact.

Somewhere a couple years ago, I recall seeing a similar comparison based on pure lap times. The drift car lagged significantly behind in absolute time, which I still say, it it isn't just about getting there first and it involves scoring for "style" then it is motorized figure skating. That doesn't mean that drift drivers suck nor that drifting isn't a legit sport, it just doesnt turn my crank.