Structural racism exists, but so does individualized racism, where someone acts on racial prejudices even if they lack institutional backing.
If a black American manager gives their white employees all the shit assignments because they don't like white people, that is individually racist, even though the U.S. is structurally racist against black people. Similarly, you can point to racist actions white people take against black people that are much more individualized than structural. Some white asshole who walks into a black neighborhood and shouts the n-word until he gets beat up is being racist, but that doesn't amount to structural racism. He's not redlining, he's not writing carceral policy to target black people, he's not running a highway through a black neighborhood.