CJB5252, your Trent article in no way supports your statement that:  "The "white" judge let the "white" protesters off with a warning, and sentenced all the First Nations protesters, including a professor at Trent University, to time in prison."

(It's also incomplete.  An appeal a few months after the article was written reduced the fines to zero)

The reason for the sentences and fines in the first place was the refusal by the two professors to abide by a court-ordered injunction.  Jail is common in such circumstances for, example, labour leaders.

One of the reasons for the successful appeal was the fact that the two professors were first nation people - which goes in the opposite direction to your claim.

For the full appeal decision, see: 
https://www.canlii.org/en/on/onca/doc/2008/2008onca534/2008onca534.html?searchUrlHash=AAAAAQARInJvYmVydCBsb3ZlbGFjZSIAAAAAAQ&resultIndex=5