Which is why it was chosen. It's not obvious. It's just a red triangle.
...so what's your hypothesis here? That he told them to use a near-nonexistent symbol as a secret message to the, maybe 5 people in the world that remembered that symbol?
Does that sound like a credible theory to you?
...or isn't it more likely that some stupid intern just fucked up?
Using really far-fetched nazi symbols in campaigns seems like a smart move if you want maximum attention and for your opponents to call it out, and then most people going: "?? whats nazi about a triange??".
Why would a campaign intentionally risk the political fallout of using Nazi imagery when that candidate is already the established favorite for white supremacists? There's enough factual shit to be disgusted about regarding Trump, we don't need to be fabricating conspiracies out of geometric primitives.