Mirza Ghulam Ahmad Qadiyani VS Prophets from Allah swt

Mirza Ghulam Ahmad Qadiyani deemed himself superior over all Prophets by claiming that he never made mistakes yet other Prophets [pbut] do make them.

He says in one of his book : 

"Without any doubt what is absolutely deduced from these things is that Prophets and Messengers can make mistake while intrepreting and understanding the Revelations"

Reference : 

Ruhani Khazain - Mirza Ghulam Ahmad Qadiyani // Vol 3 // Page 472 // Edn. Qadiyan Punjab. 

Now about himself he writes at another place : 

"Without doubt God never leaves me with a mistake, even for the duration of blink of the eye; and He protects me from every mistake and protects me from the ways of satans.”

Reference : 

Ruhani Khazain - Mirza Ghulam Ahmad Qadiyani // Vol 8 // Page 272 // Edn. Qadiyan Punjab.