I don't believe so. The first fight was just completely different (Cotto fight). Cotto was drawn into war straight away and hurt quite badly as early as the second round.
I think they saw Marg struggling with weight and not looking too good going into the Mosley fight and tried to find a way to beat him and still look impressive, as they knew that Mosley was a seriously tough hombre and had never been stopped before or never really tired badly in the late rounds, like Cotto had.
I think it was a bit of a desperation act and Nazim was quick enough to catch it. I just don't believe that anyone can go one, two, or even three massive, PPV, HBO, worldwide boxing fights without someone noticing something straight away.
I think you just need to watch the first four rounds of their first fight to see just how different it is. Cotto doesn't move away, he doesn't clinch and doesn't fight smart and he takes a serious beating in just those first three rounds to the body and face. He took more punishment and got hit more in those first 3 or 4 rounds than he did in the entire second fight combined. Different fighters, different times. You can't look at both fights and argue from that alone. If Margarito had been the same fighter, landed the same punches and Cotto had fought the same way, then you might be able to say "Hey look, his punches didn't bust him up as much", but the Lujan ear thing was because of Lujan's cauliflower ear from wrestling and it swelled up from all the punches landed to the side of his head. That's not that big a deal.
Most of the guys he was knocking out between everything were chumps anyway, and had been knocked out by other guys too.