A silencing tactic used against male feminist allies commenting on sexist incidents is to point out that an ally is not a woman and thus can't identify sexism, or is patronising women by identifying sexism and thus presuming women are weak and need help and taking care of.
It is in fact possible for intending allies to be condescending in their actions, but the mere fact of being male and speaking out against sexism is not automatically so.
Examples
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