I mean from personal experience I've done things I thought was funny but ended up backfiring, that Boston costume idea is actually pretty funny because my type of humor is like family guy/Tosh.0, I am too black but I put myself in her position and think the costume wasn't that serious to lose her job
Bad things have happened in history but we still make holocaust jokes, there's tons of black jokes online, there's other offensive picture on google, but I'm pretty sure no one has gotten fired from their jobs like this girl did