The spinning of turbine blades
"Carwyn needs to remember that respect is a two way process, not a one way street".
The UK Government source was left pretty unimpressed by the events of the last five days or so, as the Welsh Government announced its "new" policy on windfarms in mid Wales - the suggestion from the London end being that governments do sometimes score points off each other but that the First Minister's were at the cheaper end of the scale.
Last week, Carwyn Jones announced that, in the wake of the mass protest outside the Senedd by campaigners from Montgomeryshire concerned about the impact of turbines, pylons and a substation planned for their area, he was calling on the UK Government to respect the limits set out in his government's own planning policy, TAN 8, when making final decisions on whether large wind farms should get the go-ahead.
This was because developer interest in the areas the Welsh Government had identified as suitable for wind power had exceeded their expectations.
Sticking to the TAN 8 capacities, according to the First Minister, means there will be no need for the large pylons or substation that's caused such anger locally - as long as UK Government ministers put a halt to those greedy developers who are itching to carpet upland Wales in turbines.
The response from the industry is telling, however. There's a fascinating analysis of where Mr Jones' statement leaves the Welsh wind industry here.
A spokesman for the windfarm industry body Renewable UK said: "TAN 8 is a Welsh Government policy - wind farm developers are only building where we have been told. Since TAN 8 was introduced in 2005, the Welsh Government has doubled the target for onshore wind but not identified any new sites."
So - don't blame us is the message from the developers.
The second part of Carwyn Jones' statement on Friday was a demand for Wales to have the right to decide on major energy projects like large wind farms.
This may have sounded familiar to some. In fact, the demand for control over energy schemes has been established Welsh Government policy for some years now.
Mr Jones travelled to London yesterday for a meeting of the British-Irish Council to make his demand in person and to raise "the impact of the UK Government energy policy on Wales and Montgomeryshire in particular". Not the impact of TAN 8, or those Welsh Government targets, you will note in passing.
After his meeting with the UK Energy Minister Charles Hendry, Mr Jones issued an official statement.
"Following my representations to the UK Government today, the UK Energy Minister has confirmed that he will be considering our calls for greater powers in this area, and will be responding shortly.
"I look forward to being able to progress this issue further."
No sooner had this gone up online yesterday evening than the phones lit up from the Department for Energy and Climate Change. It's fair to say they did not regard this as, how can I put it, an accurate representation of the meeting between Mr Jones and Mr Hendry.
A spokesman said, "The policy on devolving energy powers to the Assembly remains the same as it did under the previous Westminster Government. Charles Hendry explained he had set out the position in November and it remained the same today."
A Welsh Government spokesman responded, "The statement by DECC is a slap in the face for the people of Wales."
The thing about political tactics is they're a bit like the clear, fresh air the Welsh Government has been seeking to put between iself and Westminster - useful stuff but so much the better if you're not able to see it. Over the last five days, it's been fairly easy to discern the First Minister's tactics in relation to mid Wales wind farms.
Start by laying the responsibility for the situation at the door of the UK Government.
Play down the fact that it is your own government which has set the rules.
Recycle a demand for devolution of energy powers which has already been turned down.
Then claim a "slap in the face" for Wales when the UK Government stands its ground.
The wind turbines aren't the only things to have been rotating furiously, it seems.
But one crucial point not to be missed here: the Welsh Conservatives and the Welsh Liberal Democrats are entirely in agreement with the First Minister that the energy powers he's outlined should indeed be devolved. They simply object to his timing and attempts to deflect attention from "the real mess" of his own energy policy, as they see it.
So, if three months after a referendum is the wrong time, if Mr Jones keeps asking - the right time will come?