Building Bazaars as Hiawatha - What?

[Gucumatz]

I joined a friends multiplayer game at his request and I took the place of Hiawatha. What I found strange was I was trying to choose the Arabs, and had selected the Arab AI for me to replace. However I loaded into his game as the Iroquois. With one strange detail: I could build the Arab unique items.

I have to ask has anyone else encountered this bug? I never met this before the patch

 

[Tabarnak]

I also never heard of this kind of bug.