Ferreira said the South Africa Sanzar judiciary was aware of the time difference between South Africa and New Zealand and took that into account when making its decision.
The judiciary took the unusual step of suspending Nonu for a week for a dangerous tackle in a Rebel Sport Super 12 match against the Sharks, but the suspension didn't include a match.
"It was more of a warning from the committee," Ferreira said.
"The committee was aware of the time factor and took that into account. But they felt it didn't warrant suspending the guy for a match. The match was played on a Friday and they suspended him until next Friday. They were aware the Hurricanes were playing on Saturday at home (Wellington).
"Because he was charged under the Sanzar rules and he committed an offence, action had to be taken. The extent of the action is entirely up to the judiciary committee. I think it was commonsense."
New Zealand Rugby Union deputy chief executive Steve Tew said he couldn't comment specifically on the Nonu case.
"I guess it's possible they have decided the offence did not require a game to be missed, but that some punishment was still required," he told the Dominion Post.
"It's unusual that he won't miss a game, but he is affected. Our players lose half their week's pay when suspended; they may have taken that into account as well as the fact that it will go on his record."
Though there were International Rugby Board guidelines on punishments, it was up to each Sanzar judicial committee to consider the mitigating factors in individual cases, Tew said.
Suspended players were free to train, unless the offence was doping.