I've been lucky enough to get two tailoring recipes in one ( failed ) craft before, but never three. It's not so far-fetched that you'd gain multiple recipes, rapidly, due to skill level / recipes available to you.
There are some default recipes when you reach a skill level in crafting--in this case lvl 25. They don't appear exactly at the level anymore, but at some random point after that. Presumably, this is to keep characters with no recipes from using the level skill gains to get recipes where they have none. These recipes include the non-set helmets (Apprentice Cloth/Leather/Bone/Grass Helm), light and heavy grass plates, and several weapon recipes.
The OP had reached the point where he'd gained these default recipes. Weapon and armor crafters should see these multiple recipe gains. I haven't heard of this in tool crafting and do not know if this happens in Architecture.
But if there is no real limit in how many recipes you can discover at once, then maybe is viable. Maybe you got 10% chance for the first 5% for the second and 3% for the third in one go.. It's a guess, nothing is confirmed..