When Greg Combet faced the royal commission into Labor's home insulation scheme he fought back tears in reflecting on the deaths of four young men.

The former climate change minister, responsible for the $2.5 billion scheme in its final days, expressed horror at the ''unscrupulous people'' milking the batts installations and conceded the entire program was ''fundamentally flawed'' from the outset.

Historic appearance: Kevin Rudd leaving the inquiry. Credit:Glenn Hunt

His appearance on Friday, a day after former prime minister Kevin Rudd became the first PM called to a royal commission, was the type of theatre the Coalition may have anticipated when it pushed ahead with holding the public investigation at an estimated cost to the taxpayer of $20 million.

But did the political theatre reach its audience? As the final hearings of the royal commission wound up in Brisbane on Monday, Labor Party insiders said it did not.