When you're in a hole, stop digging. Could Coles, Woolworths settle with the ACCC on fake discount allegations?

Trust, reputation, social licence.

Words we often hear from big corporates as they weave their way through a myriad of political, regulatory and consumer hurdles where a single mistep can unravel decades of a hard-won family friendly status.

The major banks lost plenty of reputational skin in the financial services royal commission where evidence that trusted institutions put profits before people shredded corporate careers.

National Australia Bank chief executive Andrew Thorburn and his chairman Ken Henry were the high profile bankers to walk the corporate plank.

Now it's the turn of the supermarket giants Coles and Woolworths which stand accused of misleading consumers about price discounts on hundreds of products.

While the allegations are yet to be tested in the Federal Court, the no-nonsense pursuit by ACCC chair Gina Cass-Gottleib only confirms suspicions held by consumers that promotions like "down down" from Coles and "prices dropped" from Woolworths are dodgy.

Or "illusory" as Gina Cass-Gottlieb claimed yesterday in a full court media conference that mirrored the televised drama from the tough cops on the beat like the US Securities & Exchange Commission.

Ms Cass-Gottlieb is on a roll after targetting Qantas last year for selling fares for flights that didn't exist as the airline's reputation unravelled resulting in the emergency exit of chief executive Alan Joyce and later chairman Richard Goyder.

Fearing a long-running battle in the Federal Court, new Qantas chief executive Vanessa Hudson settled with the ACCC for a $100 million penalty and $20 million to compensate jilted customers.

Coles chief executive Leah Weckert says the company intends to defend the allegations while her Woolworths opposite number Amanda Bardwell plans to "carefully review" the claims and while continuing to "engage with the ACCC".

But behind the scenes, it's likely that legal teams from Coles and Woolworths will be examining the scenario of a settlement to cauterise the reputation, political and investor damage.

By yesterday's close, Coles shares had plunged by 3.3 percent with Woolies ending battered and bruised down 3.4 percent.

Another less tasteful option would be for Woolworths and Coles to admit they've been caught red-handed or at least have been tricky with their discounts where consumers have allegedly been duped.

While that's unlikely in the immediate term, a full apology to angry shoppers would go some small way to rebuilding smashed trust and reputation.

It's worth a flashback to Banking Royal Commission and Kenneth Hayne's findings of poor ethical and in some cases unlawful behaviour.

Former Queensland premier Anna Bligh - now chief executive of the Australian Banking Association - confirmed a "dark day" for the banking sector and vowed to rebuild trust.

Or maybe - in the case of Coles and Woolworths - it's time to consider the first rule of crisis management.

When you're in a hole - stop digging.