This link in Third Sector News refers to a Sunday Times article, which I didn't get to see. It would appear that Mr Williamson is back in the limelight after the Charity Commission acknowledged failings in its previous investigation. I think it refers to a Strictly Come Dancing-themed event that lost the charity over £100,000 - apparently, nearly a year's pay for the CEO.
I also note that in their response, the charity spokesperson referred to "over 30,000 missions" - are they recording airtests, training flights and early cancellations as 'missions', or do they use the same criteria as other UK Air Ambulance operations?