Some of you are very adept at dancing on pinheads it seems. :sarc:
Not wishing to derail the discussion, but rather to get back to a comfortable level 1 or 2. While not mentioned in your original scenario this is definitely worth bearing in mind.
Ask yourself- Is the defender on side?
Should he actually be retreating behind his own kicker instead of preventing this QTi?
[LAWS]A short WR clip gives a couple of practical examples.
Offside when the ball is kicked to touch thereby preventing quick throw ins
WR puts it like this:
Zero tolerance to offsides from kicks to be strictly policed
Players in front of the kicker of their side must not advance until onside and offside players within 10metres of the ball alighting must retire and continue to retire until outside the 10metres or put onside[/LAWS].
My point being, that while the law isn’t clear on your scenario, the situation might not arise all that often if we enforced existing Laws a little better. QTi is often only on when the opposition kick deep, for the OP scenario to exist there is a strong chance the preventer is not onside.