I think so, yes. In the rule book, boarding even says "There is an enormous amount of judgment involved in the application of this rule by the Referees," and this obviously extends to the DoPS as well. To pretend that there is anything black or white about the rule is a bit disingenuous.
Dermott gets injured here because of the way he landed on his wrist. George Parros' team has to decide whether hits like this have carry a high risk of a similar result, as well as how much of a role the boards actually played in the incident. I think the decision is perfectly justifiable that this was not an excessively dangerous play, and that the outcome that eventually occurred was highly unlikely. I get if you disagree because of the amount of discretion, but I don't think you can point to this as a ruling that contradicts the rule book.