New here in recent years --- after a long hiatus from the old whoopass blog site. Previous handle was Sambito.
My experience of racism is that it exists at every level of society from internal thoughts of individuals to the systemic nature of institutions and their biases. Research actually confirms this, but this is such a charged series of issues (intertwined with family, culture, oppression, gender etc.) that people tend to solidify their opinions around racism early and tend to get more entrenched -- often with confirmation bias --- looking for those parts of lived experience which confirms their biases.
Anyhow, I think its better to distinguish between two of the more pernicious forms of racism (Overt/externalized and Institutional/internalized) versus some of the more innocuous "gotcha" types of humiliation for all involved --
Externalized or Overt Racism (where the idea is the person feels confident enough in the dominant culture to use race/appearance as a cudgel to abuse, shame or establish an unchallenged belief) is what 90% of us think about when we think of racism -- Often, this is a binary or black and white, or us versus them kind of ignorant comparison.
What is more relevant and pertinent is, however, institutional racism where public policies often reflect the dominant culture and disregard the implications of historically disadvantaged populations. The minimization that racism no longer exists in any culture is a part of this --- "there is nothing here to see" kind of institutional forgetting so necessary to maintain dominant supremacy.
In other words, when racism is in your face or completely ignored as not occurring are most damaging forms.
When we think of Gurriel, I think he was trying to be funny with his friends - at the expense of Yu. No excuse, but hardly putting up a billboard and trying to send a message of hate. And, I have not yet read his respond in entirety, but he sounded contrite and does not appear to be minimizing it as not happening.
The sad truth is all of us by virtue of living in this society have the capacity to be racist. Owning our mistakes and trying actively to prevent them from harming people is what we should be focused upon.