The evidence before the robodebt royal commission is just heartbreaking. Broken person after broken person, the collateral damage of the Coalition of cruelty. We should be embarrassed and ashamed.

But one person's evidence should frighten us. There was no heartbreak, no tears - but an example of the shocking erosion of the values of democracy.

As one former public servant described it to me, Renee Leon's evidence displayed the utter corrosion of the Westminster system.

Renee Leon was a senior public servant for a very long time. She ended up clashing with another very senior public servant Kathryn Campbell.

The evidence given by Ms Leon suggests Ms Campbell was "responsive to the government's policy agenda".

Ms Leon was somewhat less so. Leon was concerned about the legality of robodebt but says her minister wanted to double down (a claim he denies).

She claims to remember the interaction clearly (although she was too polite to take notes in front of him).

"I thought my advice was obvious, really, that there wasn't any other course to take, that it seemed the only thing for an organisation that had been found to be doing something unlawful to cease doing it and to remediate and to apologise. That seemed obvious to me. So I was surprised and shocked to get such a strong rejection."

Leon was terminated not long after: "We were never given a reason for our termination, commissioner, but I did think that there was some commonality amongst the five secretaries who were terminated, which was that we did believe in frank and fearless advice."

Turns out difficult advice was usually provided orally, according to Leon, who said on Tuesday: "I would have said that that was the case when I was the secretary of Employment, as well as when I was the secretary of DHS.

"But it certainly became more and more pronounced in more recent years, and there was much more visible feelings that there were consequences for people if they were unhelpful to the government.

"So people became more anxious to be seen as compliant with ministers' expectations about how things would be done. But there had been, I think, a longstanding and undesirable practice for things that were problematic not to be written down."

And of course, maybe to temper that difficult advice.

These are all terrors you can read in the daily transcript of the royal commission where yesterday Stuart Robert admitted loyalty to his cabinet colleagues counted more than his own beliefs about a potentially flawed scheme.

There is much to horrify in what we have heard at the royal commission but I don't think anything is more horrific - in a systemic sense - than the evidence of Leon.

Mind you, not shocking enough for the ABC's 7pm ACT television news bulletin that night as far as I could tell. Weird news judgment when your audience is filled with politicians and public servants. Fortunately, it ran nearly everywhere else and of course online and on the news channel. But 7pm bulletins are meant to be the news programs of record.

Under the Coalition, many public servants did not serve the public. They served their ministers.

I hope to God that's changing with the change in government. Marie Coleman was devastated by what she heard and saw on Tuesday.

Coleman, PSM, AO, was the first woman appointed to run a statutory authority (by Gough Whitlam and Coleman has contributed to the new book Women and Whitlam), has been an activist for decades and turns 90 today.

Next week, the Foreign Minister Penny Wong will pay tribute to Coleman on International Women's Day. We should all give thanks for her existence and I am so lucky to know her and to vacuum up any advice she gives (which includes the odd dressing-down when she feels I've been sucked in).

She watched Leon's evidence: "I was so impressed by her quiet dignity."

Coleman is shocked by what modern conservatives have done to the public service.

"I am deeply disappointed and upset that the SES, in their zeal to be responsive, were prepared to completely ignore [legal] advice."

I asked another former public servant and academic Meredith Edwards who knows the system inside out. She says that if you were in the public service back in the '80s and '90s, Renee Leon's evidence would have surprised you.

Not now though.

"There has been increasing politicisation of the public service over a long period of time but accelerating over the last decade or so. Many of us who may be now a bit distant are getting messages of public servants being extremely risk-averse, and having to be overly responsive to the wishes of ministers," she says.

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Edwards says she was talking to a Liberal staffer (when the Coalition was still in government) about public servants.

The staffer said: "They seem to ask me how high to jump."

It should not be this way. The problem lies not with the public service but with ghastly politicians who want to impose their ideological positions on an unsuspecting public.

As Edwards puts it, this is tricky.

Public servants dealing with politicians need to feel confident that they have the trust of their ministers. But it seems as if these Coalition ministers only wanted advice they agreed with.

Too early to tell. But we all need to keep an eye on the comings and goings of the public service.

Through the ministrations of sainted commissioner Catherine Holmes we've had an extraordinary opportunity to see what happens behind the scenes.

Can the public service recover? Hard to know. Can an entire generation of bureaucrats be reprogrammed to stand up to ministers?

Hard to do much else except hope that the public service knows how to weed out suck-ups.