If you were using StreetComplete I don't think you would have run into that. StreetComplete is very beginner friendly, and I don't think you can use it to mark a road as prohibiting pedestrians (which, as you discovered, is easy to get wrong if you don't understand what you're doing). You can use StreetComplete to mark whether there's a sidewalk or not, but I don't think anyone would object to you marking roads without sidewalks as not having a sidewalk.