Not trying to be a Scrooge, but unfortunately 99% of castmembers have no clue what they are talking about when it comes to telling real pins from fake ones. They are not truly educated in any way by Disney in how to tell, and all of their knowledge comes second hand from other cast members who think they know what they are talking about. I ran in to a cast member that said a pin was real if it had a mickey head shaped back on it but that all fakes came with metal or round backs. Are you kidding me????
The extra tiny posts or nubs have nothing to do with the legitimacy of the pin. Those are only there to help hold a pin on. I have seen plenty of fakes that have had them. As far as pins being prototypes; anything made in the last 3-4 years should have a tiny "AP" for Artist Proof or "PP" for pre-production stamped on the back. Otherwise, it is not. Pins 5 or more years old or older do not always have these marks, making it really hard to tell. You would have to receive the pin from the person that originally purchased it from Disney to guarantee that it is what they say it is.
And yes, mis-spellings occur and are a sure sign of a fake pin. Otherwise take great advantage of the information in the Pin Comparison section of the forum, especially the stickied threads at the top. One is a quick pamphlet DPF "How to Tell" guide and the other is more in depth on how to spot fakes.
If that mowgli pin is a PP or an AP, it should have an AP or PP stamp on it. I have to say, that is probably the laziest, worst looking fake pin I have ever seen. The guy that traded it to that cast member probably was laughing the rest of the day.