How was any of this safe or legal? Surely there are laws against this?
On the legal side - although I don't know the extant legislation, the aviation law is easy enough to check. Other rules are less easy to pin down and verify - such as insurance requirements for both airport and aircraft operator, normal operating procedures and authority to deviate from them. As for whether it is safe - well, it appears that the aircraft got away without incident or issue. (With one or two possible exceptions) we can only guess at what the plan was should the aircraft have had a problem shortly after departure but given clement weather I suspect that entirely suitable and safe options might have been available. It is sometimes useful, or even important, to remember that ATC is one part of a system - in the UK, historically there have been requirements for ATC service in situations where elsewhere no similar obligations have existed. This can lead us to imagine that things are not safe without some form of ATS whereas elsewhere people and carry on flying quite happily whilst wondering what all the fuss in the UK is. I'm not advocating that we can do away with ATC, simply trying to point out that in the sort of situation described safety is not likely to have been compromised to any great extent.
The UK traditionally has also rather over-engineered some aspects of ATS provision (although the rest of Europe is catching up fast) making it a very expensive service to provide - this might encourage alternatives to ATC to be investigated or used. Where such alternatives are legal and adequately safe why shouldn't they be used? I must stress that I don't know enough about the current dispute between HIAL and some of its employees to understand the rights or wrongs of this particular alleged event, simply trying to provide a fairly balanced view to an earlier post.
As to SARG, I'm not sure if I understand highwideandugly's comment correctly, but my personal recollection of the Scottish Regional Office (albeit from some time ago) was that it was run akin to a little fiefdom, having declared UDI with respect to the Gatwick people, where all sorts of odd things were allowed for some regardless of the rules. Times may change.....