HE ARRIVED WITH THE CAPS LOCK ON.

Or to quote Senator McGrath directly: "I BEG YOUR PARDON?" and "THAT IS SO WRONG!" and "I WILL NOT ACCEPT THIS!"

Somewhere on Monday night, recent Q A train wreck Teena McQueen was sipping on a cocktail of bleach and vinegar and thanking the lord for Queenslanders for making her look good. It was quite an achievement, as McGrath turned expectations on their head and ensured One Nation's Malcolm Roberts was not the program's one-way trip to crazy town, as many objectors to Roberts' invitation had feared.

In the lead up to the show - guest-hosted by a fierce and firm Virginia Trioli - there had even been a #BoycottQ A hashtag on Twitter in protest against Roberts' appearance, and to those who obliged the boycott one can say only that you missed out.

Because there is something to be said for inviting angry candidates for the federal Parliament to a national stage and letting them let it all hang out. On Monday night, boycotters and viewers alike expected Roberts to deliver the madness, as prefaced by his first appearance on Q A when his wackiness appeared close to sending rock-star physicist Brian Cox to hospital.

The flashpoints were many, but what really set off McGrath was the suggestion that he and his party were somehow in bed with either racists or political donors.

The Greens Larissa Waters: "Nothing to do with the donations from Adani."

McGrath: "That's offensive."

Waters: "You should give the money back."

McGrath adopted the Casablanca defence.

He was shocked - shocked - at the suggestion gambling was taking place on Queensland premises: "It's offensive to say that any political party will take a position based on a donation..."

The audience fell about with laughter.

And yet, he persisted: "And you should think about yourself in terms of what you've just said then."

Waters: "This is why we need a federal ICAC, and you know it."

McGrath: "I want to address that. I'm outraged, I'm actually outraged about that. It is actually offensive for any politician on this panel or anywhere to say that the Liberal-National Party or people who support the Liberal-National Party are taking policy positions based on donations. That is actually offensive and it is wrong."

Soon after, McGrath was asked about a photograph of him that featured supporters flashing a white supremacist symbol.

McGrath: "I'd never seen that symbol before and they were suspended ... that's the way it should be. And I'm sure the Greens and I hope Labor would agree with that."

The Greens' Larissa Waters: "I'm not sure Peter Dutton would."

And then it was on.

As best we can make of the shout-fest that ensued:

McGrath: "I beg your pardon. Are you serious about that?"

Waters: "Yes, I am."

McGrath: "This is the problem with the Greens. No, this is serious. You've accused my party of taking policy positions based on donations and now you've effectively, which is wrong and is offensive, and now you've effectively accused Peter Dutton of being a racist. That is wrong."

Waters: "Yes, I have."

McGrath (shouting): "That is so wrong. This is the Greens. No, no, no, I'm sorry. These just accused a senior member of my party of being a racist and I'm calling her out on that."

Trioli: "She's standing by it."

McGrath: "What's the evidence of him being a racist?"

Waters: "Look at the entire policy platform that he, as immigration minister, and a..."

McGrath, yelling: "I'm sorry! I will not accept this."

Trioli: "You don't have to accept this. We're going to move on."

McGrath (hollering, audience booing): "Where are your tears for those people who drowned at sea and were eaten by the sharks? Where were your tears there? So don't come here with your crocodile tears talking to me about what Peter Dutton and Scott Morrison did. They made sure the borders of Australia were safe and secure."

Trioli: "James McGrath, I'll ask you not to shout."

McGrath: "Sorry, they were booing me so I had to shout."

It was not the first or last time Trioli had to whack the panel into line, including during a testy argument over One Nation's policy on gun laws. Watering down? Not watering down? Trioli was sceptical.

Roberts: "You're interrupting me again."

Trioli: "I'm the host of the program, Malcolm Roberts."

Roberts: "I'm a guest. I'm a guest. You can look at me any way you want. I'm a guest."

Trioli: "It's my task to keep you on task."

And later, Roberts wanted to question a questioner: "Sue, can I ask you a question?"

Trioli: "No. No you can't."

Roberts carried on regardless.

Trioli: "I'll run this because they're paying me the big money to do so. Our next question now."

And so it went, including a stoush over veganism and "vegan warriors".

McGrath, clapping like a seal at the question and then shouting: "It's a home invasion!"

Trioli: "James McGrath, the question has been asked. Let her answer it."

McGrath (animated): "Let them go to your house. What's your address? Put your address out there and let the farmers go to your house. That's what's happened to farmers. That's what's happened to farmers .... that have had these monsters, these eco-criminals invade their homes. Shame on you for defending them."

Roberts: "There's something really important..."

Trioli: "Malcolm Roberts. No."

Roberts: "What we're seeing is..."

Trioli: "No! I'm sorry the question was not to you."

It was a valiant hosting performance.

As for the guests, the only thing missing from the night was McGrath thanking Roberts for holding his beer. We assume that happened in the green room later.