Here is a short explanation of heyoka from Heyoka Magazine...
In Lakota mythology, one who lives in opposition is called a heyoka.
...
... It is said, therefore, that if one does encounter Thunderbird, one becomes heyoka, and also begins speaking and acting in an anti-natural manner. As James R. Walker explains in his work, Lakota Myth, “When one sees the Winged One, he is heyoka and ever after when he speaks, he says the opposite of that he would say and when he does, he does the opposite of that he would do.”
The
entire article is quite amusing.
Linda was just bringing attention to heyoka opposition or backwardness. Not saying they shouldn't be listened too, just be aware of how they speak. Red Elk seems to speak forthrightly, he is trying to reach the non-native audience afterall. But knowing something of the heyoka might be helpful.
Watch out for the tricksters!