He's good at calling people to account. That, fundamentally, is the role of the Opposition. When Muller finishes his ill-advised media training, which only appears to be making things worse, perhaps he could get on to that.
But back to Act.
The party has pointed out that the Government is cunningly continuing its taxpayer-funded "Unite for Recovery" campaign, which was - of course - in a previous life, "Unite against Covid".
Acceptable then, not now.
Now that that's finished, Seymour's questioned whether spending taxpayer dollars - on what's effectively a propaganda tool for the Government - is still acceptable.
Not only that, the ads are triggering anxiety in some people.
Some have written to me, saying they find the ads distressing, that they associate them with fear.
One woman said her anxiety levels rise every time she hears the ad. She said, "I really wish they would stop and think, there is far better use of our taxpayer money than continuing to instil fear in us".
So why do we need this Covid-wrapped taxpayer-funded advertising making obvious suggestions such as "shop local"?
Could we not have figured that out for ourselves?
As of this Friday, the country enters the official pre-election period which means very strict rules for political parties come into play. One of which is that "Government advertising should be presented in a manner which is … free from partisan promotion of government policy".
Which is where we have another problem.
Because Seymour points out the "Unite for Recovery" website promotes at least a dozen new Labour Government Covid-19 programmes. These are, in effect, promotions of its party policy, which is in a clear breach of the Cabinet Manual guidelines.
But they're banking on us not noticing because while they can keep us in a "crisis mode" mentality. The Government continues to position itself as "saviour", Seymour says.
"Labour doesn't want the crisis to end. It has managed to control the narrative, the people and the polls. [It] is desperate to avoid a return to normal politics. That would mean having to talk about its failings."
So will this open honest and transparent Government choose to play by the election rules or not?
Party leader Jacinda Ardern herself, back in January, called for a "factual" election campaign, one free of misinformation, a principled, open, transparent campaign, she promised.
Is that what we're getting?
Or does their new addiction to crisis management (also known as control) overshadow everything now?