I think a big factor was the PR disaster that Smith interview was. Optimally, he should've obfuscated it by calling it a misunderstanding of the rules or a honest mistake and saying we'll take whatever punishment the ICC gives us and ****ed off and waited for the dust to settle. Instead, he gave a clueless pollitician speech with stuff like "this calls into question my integrity, integrity of the team, integrity of the leadership group etc.". The world was going to treat it as another ball tampering incident, get mad for the weekend and move on. Smith made it much bigger though, he made this issue of the integrity and morality of the Australian Test captain and by extension, Australia. I was just cringing hard at how much unnecessary damage he was doing to himself in that interview.
He also should've limited exposure as little as possible by saying as the captain he takes responsibility for the indiscretion and all consequences. Instead, with the whole 'leadership group' sthick, he made it seem like a criminal conspiracy involving four layers of managment to gain an advantage. The amount of times he used the awful phrase made him appear insincere and as if he was deflecting personal responsibility.
PR people are panned a lot for producing the current culture of mundane interviews but this is one instance wherein it would've helped a lot to say "it's a misunderstanding/mistake, against the rules, will accept icc consequnces, thank you, **** you, bye".