Listen that was a close fight where either fighter may have won the fight.
Back in the day when either fighter is barely connecting, judges usually lean more towards the aggressor, this is to encourage future fighters to risk more--to throw more. Obviously this isn't good for the health of the fighters but this is good for the health of the sport.
The arrival of Mayweather as the new cash cow of boxing in America may have temporarily threw a curve ball to the default aggressor's era into a defensive era; but unfortunately for Rigo that era may be over and he's now fighting at this era ready to transition back to aggressor's era.
Think of what happened to Pernell Whitaker in the aggressor's era, that's 10x worse than Rigo. But in an aggressor's era, judges just lean more on aggressors because their priority is the overall health of the sport.
Nah.
Context matters. Casimero is the champion. Rigo is the challenger. Judges ALWAYS give the champions the benefit of the doubt over the challenger. Hence, it's the burden of the challenger to bring the fight to the champion to show that he actually wants to win the belt on the line.
Rigo didn't do any of that.
Rigo might've won if they upgraded his belt to WBA Super and this becomes a unification fight. But in this case, Rigo is the challenger. He didn't do enough to get the nod.