Laas described the administrative penalty of R309m imposed on his company as "severe", and the collective R1.46bn penalty for 15 major firms was far more than a "slap on the wrist", the newspaper reported.
"One almost gets the impression that the construction industry has been lined up in front of a firing squad with government firing the shots, everybody firing the shots," Laas said at a briefing.
"I am not saying we do not deserve it - you cannot find an excuse for what happened in the past, but we came forward with the intent to clean the industry up and move on."
"I am just concerned that it will be very hard for the [Competition] Commission to find this level of voluntary disclosure if they want to embark on similar processes with other industries."
Last month, the commission fined 15 construction firms a collective R1.46bn for collusive tendering related to projects concluded between 2006 and 2011.