I'm an amateur boxer, so I can kind of weigh in on the outcome. Ortiz headbutted Mayweather, and intentional or not, he loses a point in that round, and the referee breaks them up.
Here's where it gets tricky. In amateur boxing, when you get broken up, you don't throw a punch until the referee says 'box'. In professional boxing, it's as the saying goes 'Protect yourself at all times." The referee made it clear to the judges that Ortiz lost a point, lined them up, and Ortiz moved toward Floyd, to apologize again, and Floyd hit him with a 1-2.
Was it legal? 100%. Ask Joe Cortez, the presiding referee. Was it dirty? Extremely. But everyone overlooks the fact that Ortiz headbutted Mayweather, which is also extremely dirty fighting.
Add to that the fact that Cortez saw the right hand, saw Victor fall, but gave him a 10 count, not a standing 8. If it had been an illegal shot, it would have been a DQ for Mayweather, or Ortiz would have been given 8 more seconds to get to his feet.
With a record like Mayweathers (41-0 going into the fight), you wouldn't tarnish it with a DQ.