Just it's a latin crowd. They encouraged his #1 hero boy loudly and passionately, but always being respectful and thankful to Nole effort, even when he faced them aggressively punching his chest, on the contrary, no problem with that, this is Sparta, and gladiators & "macho men" are welcome here...
Did they are nationalist? Come on, nothing new under the sun.
Unlike many other places in Europe is very unusual to find violence in any sport event in Spain, only passion and joy so stop complains, please!