The transcript of the tape-recording of Rupert Murdoch's meeting with arrested Sun journalists makes for fascinating reading. It presents a picture of a very different private Murdoch from the one who professed his humility in public.

The media mogul emerges as the man I recall well from the years I worked with him – dismissive of authority, railing against a variety of "establishment" enemies and defensive of the paper's news-gathering methods. It is a glimpse of the authentic Rupert.

The only thing missing from the transcript – here on the Exaro site – is the number of times he slapped the table, one of his tics when he is angry. Though one occasion is mentioned, according to one of those journalists who attended, it happened many times throughout the 45-minute meeting on 6 March this year.

Let's consider first what Murdoch says in response to the concerns aired by his staff about the way in which News Corporation's management and standards committee (MSC) has provided evidence to the police.

He rejects the staff's anger being directed at him, saying: "I'm just as annoyed as you are at the police … you guys got thrown out of bed by gangs of cops at six in the morning."

He admits to a measure of panic as the reason for setting up the MSC to provide information to the police: "The police were about to invade this building … it was done to protect the business."

Asked whether he would support journalists in the event of their being convicted, he suggests that jail terms would be "outrageous".

They were arrested during Scotland Yard's Operation Elveden investigation into illegal payments to public officials. But Murdoch tells them they had done nothing "that wasn't being done across Fleet Street".

And then came a familiar Murdoch theme throughout his career. "We're being picked on," he says, citing both "the old right-wing establishment" and "the leftwing get-even crowd".

He talks of the News of the World in personal terms: "We got caught with dirty hands, I guess" before launching into a further attack on the police: "The cops are totally incompetent … It's just disgraceful what they're doing … It's the biggest inquiry ever, over next-to-nothing."

A crucial section follows when one of the journalists, who had been with The Sun for under 10 years, points out that the paper's "working practices… were ones that I've inherited, rather than instigated."

Murdoch replies in what will surely be seen as a crucial statement about The Sun's culture and his acceptance of it:

"We're talking about payments for news tips from cops: that's been going on a hundred years, absolutely. You didn't instigate it."

In my opinion, this offers the journalists a crucial plank of mitigation for their actions. It is also a reminder of the occasion in 2003 when the former Sun editor, Rebekah Brooks, told a Commons select committee that the paper had paid the police for information.

Murdoch continues: "I would have thought 100% … at least 90% of payments were made at the instigation of cops saying, 'I've got a good story here. It's worth 500 quid' or something. And you would say, 'No, it's not' … And they'd say, 'Well, we'll ring the Mirror…' It was the culture of Fleet Street."

At one point Murdoch also lays into lawyers, accusing them of getting rich by trawling through millions of emails [as provided by the MSC].

Asked what would happen in Murdoch's absence – presumably, his death – Murdoch said decisions would be taken by his son, Lachlan, or Robert Thomson [who has subsequently became chief executive of News UK].

In terms of the News Corp succession, the mention of Lachlan – who doesn't even work for News Corp – was an eye-popping statement.

But the real significance of the tape is that it reveals the true, unexpurgated Rupert Murdoch. As I have said often since the hacking scandal first broke, as the man at the top I believe he has been responsible for the journalistic culture at Wapping. This tape appears to prove my point.