Basically, yeah, its enough work keeping goals that are kicked in off the board, let alone disallowing one that banked in off someones ass.
I dont mean this in a critical way, but you have to keep in mind, pre-1990 or so, the human resources assigned to work an NHL game werent really much more than what youd have for ... a 2024 junior C game maybe? You would have had the goal judges which I dont think the junior C game has, but only 1 ref and 2 linesmen, a timekeeper, and thats it. No video review, no cameras flagging incidents behind the play, if theres an attempted homicide on the ice during a rush, chances are the only official witness is the trailing linesman, which makes it hard to cite multiple witnesses if you want to suspend a guy for life.
You just couldnt do something crazy like banning all deflection goals off bodies because they could never call the game correctly to a standard that tight with the resources they had available