using technicalities to not honour the spirit of tax law used to be called tax evasion
No it didn't, it was/is called tax avoidance and it has always been legitimate. The difference is primarily one of intent. If you honestly and reasonably (i.e. not culpably irresponsibly) believe you've found a technical ruse to avoid paying tax then that's legal. If you're wrong then the worst you can generally expect is a retrospective bill (with interest). Tax evasion is dishonestly misrepresenting your affairs to reduce or eliminate your tax bill and can land you in jail. Mistakes are not fraud and being wrong doesn't necessarily make you guilty.
The Government is not allowed to win with the argument: "Yeah, yeah whatever! It doesn't matter what Parliament SAID, what they MEANT was...". Damn good thing too given the abuses it would lead to.