This is worrisome

I'd presume it was also flying into a massive headwind which reduced it's actual speed and ate more fuel than expected. Not sure if weather is factored into fuel calculations, although I would think it would be for situations like this.

Absolutely, fuel reserves are very much accounted for. So are alternate airports, multiple aborted landing attempts, forecast weather, and many other factors which provide crucial safety margins (or are supposed to). If the “six minutes of reserves” as reported is actually true, it suggests that something went very wrong. Yikes.

The pilot had squawked Code 7700 immediately after failing to land at Edinburgh for an emergency priority landing at Manchester, fully aware of the fuel situation.
In the storm Manchester was the closest available airfield, as Newcastle was also socked in.

That day other flights into Scotland were being diverted all over Europe due to the severity of the storm, and Belfast and Dublin were also struggling.

It's difficult to see what else could have been done, except to make a hard and very dangerous landing at Prestwick or Edinburgh.

Funny how the previous week no-one reported the United flight which had an engine issue soon after leaving Heathrow and had to circle the English Lake District in about half a dozen loops dumping fuel before making a full emergency landing back at Heathrow at a remote stand with all emergency services attending, fire trucks doing a high speed follow.

"Funny how the previous week no-one reported the United flight ..."

Not so funny. I have no interest in an emergency situation that happened. The discussion where I saw this, mentioned retired air traffic controllers not flying certain airlines because of their habit of declaring "low fuel" to jump the landing queue. I would expect a low cost airline to fly with the minimum amount of fuel allowed. And I don't know how that is mandated. My concern, that I didn't see worth mentioning, was these kinds of issues.

https://news.ycombinator.com/item?id=45539943

That interpretation is disputed here:

https://aviation.stackexchange.com/questions/38501/is-it-true-that-ryanair-flies-without-fuel-reserves

edit: I am happy to wait on the investigation to sort it out. If there's even anything to sort out.

Yikes! We are flying on Ryanair from Lisbon to Manchester next month. The problem appears to be due to the extenuating circumstances of an unusual storm. Still, I’ll keep my fingers crossed.