Yep. Tired tongue that’s why he mumbles uh..uhhh.uhhhhhhh..ummmm so often.
Something else occurred to me. People whose native language isn't English would have problems forming thoughts and phrases in spoken and written English. Going further: people who are literate in their own native language will, when they learn English, become more articulate in expressing those thoughts in English also. People who are not literate and articulate in their own native language will have more difficulty expressing themselves in English when they learn English.
I have a sneaking suspicion that BO's first language isn't English and that he isn't particularly literate in that language, either.