The technical stuff!
Hmmf so thats your puzzle. Let me answer.
If the dragon punch is done with hands and the shivering attack (f,b,d p/k) is also done with the hands then the martial artist will be of dragon style. Hence the f,d,df A/C is known as DRAGON punch not tiger punch. Now in AOF1 both Ryo and Robert had dragon punch and there was only one way that Robert could be classified as tiger (his f,b,f +K). The same carries on to AOF2 where Rebert gets another tiger move (qcb +K in air). In AOF3 he has another tiger move (d+K at end of his combo) and Ryo is the same Dragon. Also in SNK vs CAPCOM chaos when Ryo and Guile are to fight
Guile : I've heard about you legendary tiger.
Ryo : You're mistaken. Its my father. I'm the Dragon.
Guile : I'm sorry but I heard that the ratty one was the dragon. (hence annoying him)
Ryo : And whom are you saying "ratty"?
Also we see that Robert is the student of Takuma who is a tiger (he has a peculiar tiger counter qcb, A/C) but we see nowhere that Ryo is the student of his father (although he learnt SOME of his techniques from his dad but only 2 or 3)
And also we see that the Kensei kicks (HCB K for Robert, db, f+k for Tak) of Robert and Takuma are resembling and Ryo has very different from them both.
By the way the style of Ryo is Hidden Dragon and Robert is Crouching Tiger.
I hope the problem is solved now ...