FoRKs and helping are similar but different processes. I can see that its hard to distinguish them but I don’t think its impossible.
I think from a design POV the reason is clear. Helping is to be encouraged and it increases the interaction between players. FoRKs are internal and though useful to colour narration are more limited to prevent a player always trying to add a FoRK all the time and slowing the game down.
The way I see it is that if you are using your stat, you have no knowledge of the task, incidental or otherwise. Always being able to FoRK would diminish these “hail mary pass” type situations alot. However, you can no nothing and still have someone show you how its done through helping.