Cotto drained is nothing more than a myth/excuse. Here is how Cotto tipped the scales in his previous fights before Pac.
04-12-2008 vs Alfonso Gomez @146 1/2
07-26-2008 vs Antonio Margarito @147
02-21-2009 vs Michael Jennings @147
06-13-2009 vs Joshua Clottey @146
11-14-2009 vs Manny Pacquiao @145
Considering the date and weight that Cotto tipped the scales during weigh in, the possibility that 1 lb will drain a him is purely BS.
And with regards to the DLH bout, Pac tipped the scales @142 in that 147 bout.