Bismillahi Al-Rahmani Al-Rahim
In sha Allah I will now be able to catch up on old questions and resume the Zad al-mustaqni` lessons.
I could not find anything that substantiates what this person has said. The closest thing I can find is a discussion over whether or not permission from the Imam is a requirement for the validity of the prayer; the mufta bihi is that it is not required. I looked in Al-Mugni, Al-Muharrir, Kashshaf al-qina`, Dalil al-Talib, and a few other books. It may be that there is a transmitted account of the Imam having this position, but if so it is odd not to find it in these books-particularly Al-Mughni.
If the people who told you this are still around, you might ask them where they found this.
It is unfortunate that some people have more zeal for finding excuses to lessen their responsibility and so little zeal for carrying it out.
And Allah knows best.
wa al-salamu `alaykum