I don't know why having a draw disqualifies him from having the record. It's called an "undefeated record", "undefeated streak", "retiring undefeated", ect. To me a draw is like a No Contest - it doesn't count, it's a write-off, it's not a win or a loss, it basically didn't happen.
Can we all agree that it's Finito Lopez, not Mayweather or Marciano, who holds the record for a champion retiring undefeated.
Here's to the Mexican legend, 51-0 baby. Mayweather needs 2 more wins to tie and 3 more to take the lead, which apparently is not going to happen.
All hail Ricardo Finito Lopez!
http://izquierdazo.com/wp-content/uploads/2013/09/finito-lopez.jpg