@bri_rodriguezzz As others have said - it could be, or not. Unless a teacher explicitly uses a racist argument to justify their decisions, it is almost impossible to know from a single case.
What’s more is that, in racist decisions, a teacher may not even be doing it consciously. That is one of the things that is so insidious about racism. A teacher may be thinking that each of their decisions are justified for other reasons, and will not even realize this until you show them that, for a giver set of qualification, they place a White kid in an e]advanced class, but will be more likely not to do so for a Black of Latino kid. The conscious mind is often pretty good and finding excuses for things that it does based on unrealized bias.
A person who has grown up knowing that racism is bad, but has also been exposed to a lot of racist education, will find themselves engaging in racist behavior, even small things like, when a person is being snappish with them, thinking “how nasty”, as opposed to “must have had a bad day”. It can also be a bit less subtle as in, when told that “Jim is in court today”, a person can make different assumptions as to why Jim is in court, based on their race.
In this case, since the teacher changed their decisions, based on your appeal, I would say that it most likely was not a decision that was made because of conscious racism. That would likely have resulted in a flat rejection of your request. So the requirement to demonstrate that this is a pattern of behavior is far stronger. In all honesty, the amount of work that this would require on your part is not worth it.
However, if you hear similar stories from other Black or Hispanic students, it may be worthwhile to look into it, if you really feel the need. As it is, you are where you need to be, and there is no evidence that the teacher’s decision was based on race. So let it be for now.