If the LOTO was desperately seeking to defend an MP from false charges, e.g if the PLP was demanding an MP's suspension for saying (accurately) Israel operates a form of apartheid you'd have a point. But given the JLM have been calling for Williamson's suspension for six months, given Williamson's support for Walker and Livingstone and baiting of Jews after the Pittsburgh attack, his endorsement of Scott Nelson etc. it's abundantly clear the dude has a problem with Jews. Running interference for this guy is not defensible.
(this thread from June should dispel all notions otherwise)
Perhaps you are alluding to a scenario where LOTO is forced, by overwhelming pressure, to call something anti-Semitic which isn't? Indeed this is a worry: imagine an MP, perhaps a shadow cabinet minister who calls Israel an apartheid state. Correct on merit but provocative and likely to cause a backlash. Would LOTO be able to say: "hang on a second that was not actually anti-Semitic because x, y & z"? He'd get laughed out. He has zero credibility on anti-Semitism. Someone who hadn't spend their political career fawning over Jew haters, someone who had removed Williamson's whip months ago, someone who had chastised Williamson for bigotry rather than giving an
interview to a Derby newspaper explicitly denying Williamson is anti-Semite: they could defend the apartheid comment, get taken seriously and perhaps change a few minds.
Jezbollah is in a bed of his own making - I will vigorously defend anyone unfairly impugned as an anti-Semite but have no sympathy for LOTO should he in future face this predicament. He she only blame himself (but won't since he's never apologised for anything ever and considers himself without sin).