This is an example of the flagrant slanders intended to destroy the whole authentic Sunnah of the Prophet (PBUH).
Imam Al-Bukhari - may Allah have mercy on his soul - was the pioneering leader of hadith science, and his collection of authentic hadith is one of the soundest books after the Book of Allah Almighty, as supported by the consensus of all the leading scholars of the Muslim nation. No one can contest this but the ignorant, spiteful, and ill-intentioned.
As for the slander that he told lies because he was a non-native speaker of Arabic, it is an absurdity which only foolish, ignorant people can accept.
Most memorizers of hadith who compiled authentic collections of the honorable Sunna, such as al-Tirmidhi, al-Nasa’i, Ibn Majah, al-Bayhaqi, al-Daraqutni, and Ibn Hibban, were non-Arabs who learned Arabic, spoke it eloquently, and authored books in it.
Indeed, some non-Arabs not only mastered the Arabic language, but also surpassed the Arabs themselves and became leading scholars in Arabic, such as Sibawayh, al-Zamakhshari, and Ibn Jinni. Should we accuse them all of lying and fabricating because they were not of pure Arab origins? This is really an obvious attempt to demolish and renounce the Sunnah based on groundless claims.