The theologian you're quoting thinks priestly confirmations are invalid because without papal approval priests don't have (or given his explanation, don't have access to) the requisite power of order.
I'm aware of this. I'm also aware that the 2 phrases "don't have" and "don't have access to" are COMPLETELY different.
a. "Dont have" = no ability to have on your own, with permission or without. (defect or order)
b. "Dont have access to" = you have the ability, but you just need access. (defect of permission)
This is all a matter of permission, law, jurisdiction/delegation. The priest HAS THE POWER to confirm, he just needs ACCESS/PERMISSION to use such a power.
The very fact that a priest is called an "extraordinary minister" implies he can confirm in extraordinary cases. A sub-deacon is not an 'extraordinary minister' for confirmation because he has 0% power to confirm. No amount of papal approval, even if the pope personally blessed him, would give a sub-deacon the power to confirm. But a priest has such a power, if 'extraordinary' cases arise.