Any evidence of this?
I didn't say it is illegal but I can't see how anyone voted to fund Northern Irish infrastructure and services above the levels of the other nations of the UK as specified by the Barnett Formula. The Conservative party should be spitting feathers over this, a large majority of their MP's are against the Barnett Formula in principle because it is 'unfair to England', yet they celebrate a deal like this.
The Conservatives are just plain desperate, they would have done anything for anyone to stay in power. The DUP actually had a choice here and their actions can only weaken the Union that they claim to hold so dear.