From the link:
"For the record:
MLH kicked him out. HTN did not.
I feel like I definitely need to make it clear that none of the directors of Hack the North were involved in this decision.
As for me, personally: I am extremely unhappy about the decision."
I absolutely respect that guy and his principles, but that's not a public statement from the organization stating its official policy, that's a Reddit comment stating a private individual's views.
One of the responding comments leads to the MLH event policy, which says "MLH reserves the right to refuse admittance to any individual at a sanctioned event." This was incredibly douchey, but didn't technically overstep the authority that Hack the North gave them when they brought them in on the event.