How single usage of bitcoin address is resistant to quantum computing _and_ replace-by-fee?

How single usage of bitcoin address is resistant to quantum computing _and_ replace-by-fee?

It is often said that if a bitcoin user uses addresses only once, then quantum computer cannot compromise their security since the public key is revealed only when the money are actually spent.

But how come an attacker could not detect a transaction, reverse the public key and forge a transaction from the same address with a higher fee before the first transaction is mined?

https://ift.tt/2tssU0A