Eh. It's a game. Nothing is invalidated if we rule different for the next game or if, as sometimes happens, we had a rule wrong. I'm not going to create a houserule to change a spell from the book just because we read it wrong the first time. We just shrug and move on. Things have changed a lot over the years, the rules are just an expression and mechanical implementation of what the characters can do. So we have dwarves that can cast spells, female characters that can have a 20 strength, any number of things have changed over time.
If we were to change something major we'll discuss it as a group and potentially keep the current interpretation for the current campaign.