I am not sure that is the case. Royalties and taxes change all the time. The key thing in my mind sis to make subtle changes. When the Federal Government made the changes to the Income Trust tax laws they should have grandfathered the current situation and simply disallowed future trusts. That would have been the fair and just thing to do.

On Royalties, they should try and keep the current structure or as much of it as possible for existing production - perhaps do a gradual increase over a 10 year period. Make some new royalty rules for new production.  

Politicians have this way of going from one extreme to the other. When they want investment they give the farm away and then years later they claim they are getting ripped off.