Rick Riodran's "apologies" are so...entitled. He didn't do research and yet pretended to. 2 characters(incl. 3 if you include an Irish demigod) are walking stereotypes. The Irish girl planted bombs, the Muslim girl is a child in an arranged marriage to an adult; and the native girl is a kleptomaniac wearing feathers in her hair. His response to being asked about this, was "Mean bullies are saying bad things :( I did some nice things, so you criticised my POC characterization, YOU are wrong >:( "
That's not an apology, but an attempt to deflect responsibility. Rick is used to praise, so he's always been considered nice—praise is when people are on their best behavior. This is his first time being called out, and we see another aspect of what kind of person he is.
His response is typical of a privileged author who has been criticised for something. Rather than saying "I did not research as I should have, and that led to stereotypically negative character traits.", he attempts to paint all critical people in a bad light. Tl;dr Don't put people on a pedestal.