Same Difference?

During our last class I began to think about a common phrase that is used quite often. This is "same difference." To me this statement seems completely contradictory. I believe it is actually an oxymoron, though I have never fully understood the purpose of these. I started to question how this phrase impacts thought processes when people are trying to categorize others. For example, in Project Mulberry, Mr. Dixon calls Julia Chinese though she is of Korean heritage. She goes on to mention how people often assume that she is either Japanese or Chinese as if those "are the only kinds of Asians anyone has ever heard of (140)." Her thoughts about why she thought someone like Mr. Dixon who was African American and had probably felt the effects of prejudice and racism would make such a careless mistake.
This moment in the book referred me back to a scene in a movie called "The Replacements" where this happens with adult football players in the lunch room. One player, an African-American, is commenting on the weight of a teammate that used to be a sumo-wrestler and calls him "Chinaman."
Player 2 responds: I'm Japanese, not Chinese.
Player 1: Same Difference
Player 2: What?
Player 1: It's the same difference man, all that woo-ka-chow (imitates Asian Languages).
Player 2: You do know that China and Japan are two different countries, right?
Their confrontation continues for a moment and starts to get physical, until a third and fourth player intervene and try to physically separate Players 1 and 2. Player 3 has an English accent, and Player 4 is the brother of Player 1. Player 3 gets the first two to calm down by reminding them that they are on the same team.
Player 4: The Mick's right, man. Chill out!
Player 3: I'm not a Mick! I'm bloody Welsh!
Player 4: What-ever man!

I shared this moment because I think it highlights the fact that such false assumptions can be made on numerous levels in regards to this idea of "same difference." The only sense I can make of this term is that it indicates that two things or people share something in common but have more pervasive differences but the viewer refuses to acknowledge the differences and lumps the two together. As we have seen and discussed, this is a very negative thing to do. It's harsh and makes the heritage of someone feel like it isn't important, as with Julia in project Mulberry.
I really appreciated her questioning of whether the intention of the assumption mattered or not. I think she is right, that not knowing and not bothering to ask is just as bad as voicing a deliberately hurtful negative assumption.

I wonder if this phrase "same-difference" should be one to pay careful attention to when we hear our students or friends saying it. Should this become one of the taboo phrases that should not be used when discussing others' identities? I am not sure, but I am trying to figure this out for myself. Please let me know your thoughts on this, as well as other phrases or words that stand out to you in a similar manner.