Of course the KEY ISSUE, is that you are not really legally self-employed when you are a pilot working for RYR or any other company, however the problem is that NO government / tax authority has had the balls to challenge this,
Oh really?
Known contract pilots with Norwegian citizenship are these days recieving a letter from the Norwegian Tax Administration stating that
all income from flying as a contractor is to be reported as salary and not business revenue (lønnsinntekt vs næringsinntekt), with only "normal" deductions allowable.
(Dual taxation agreements may limit Norways power to levy tax, but as per normal practice, if taxed owed to the other country is less, you will still have to pay the difference.)