Is the phrase "Allah knows best" after mentioning an authentic hadith of the Prophet, may Allah's prayers and peace be upon him, considered a form of doubt or disbelief in his words?

Saying "And Allah knows best" after issuing a fatwa, giving an explanation, or narrating is permissible and shows good manners towards Allah, because the mufti might miss an evidence or fail to clarify a doubt, the expounder might overlook some words, and the narrator might forget a word or narrate by meaning. This does not imply doubt, but rather an affirmation that Allah's knowledge is above all knowledge, as Allah Almighty said: (And above every possessor of knowledge is one more knowing) [Quran 12:76]. So, Allah knows best more than any scholar.