Originally Posted by Fat Sticky Topic
In RBY and GSC there is no limit like the 510 EV cap in Ruby, Sapphire, and on. The only restrictions put on the Pokemon is the amount of stat exp. it can gain in a certain stat. So yes, it is legal to have max stats in RBY.
I know this was an old question, but what Sticky Topic said isn't exactly true.
While he is right about the stat exp, he forgot to mention the effect of DV's on stats. DV's are basically equivalent to IV's in the newer generations.
In RBY a pokemon could have a DV of 0-15 in each stat. A pokemon would have to have DV's of 15 in each stat in order to have perfect stats.
I forget the exact chances, but it would be almost impossible to have a legal team with max stats in RBY, which means the guy in the tournament probably hacked his team with an old Gameshark.