The problem is less with the call and more with other calls. So many far less egregious GI calls have been made, yet this alone wasn’t (frankly, it’s closer to not than it is to GI). This SHOULD be GI, but it probably isn’t due to where Gru was on the ice. As is usual with the NHL, the problem is with the rule, not so much the enforcement.
The thing is, most infractions in a game are subjective to the Refs and are often based on whether they feel the infraction influenced the play.
I would argue that well less then 10% of infractions per game are actually called. There are a dozens of crosschecks along the boards in a single game, often zero of them are called. There are often a dozen trips in a game, and usually less than half are called. There are several interference infractions on every shift, but unless they influence the direct play of the puck, most are ignored.
So we are singling out the goalie interference as something different, when in reality, it is actually like the rest of the game, only it happens less and often seems to be more directly related to goals, which makes it feel like a larger issue.
Because GI is also often caused by contact between defensemen bumping forwards into goalies, the interpretation is more likely to be disagreed upon by opposing teams and fan bases.
The league is trying to protect goalies and has even changed how the rules are enforced, but the rule still clearly states that if a goalie is skating outside of his crease and moves into the path of an oncoming player resulting in unavoidable contact, it is not interference.
"Incidental contact with a goalkeeper will be permitted, and resulting goals allowed, when such contact is initiated outside of the goal crease, provided the attacking player has made a reasonable effort to avoid such contact."
I don't think anyone can legitimately argue that 1.) Grubauer didn't slide into Staal's path, (which initiated the contact), or 2.) That Staal could have avoided contact. Often I think the refs get it wrong, but I can't see any way that this was GI the way the rule is written or the way it has been consistently enforced for the past 30 years.