So you are suggesting that the CRA would tax the "benefit" at 100%? More likely the $100 would be included as income and taxed at the individual's highest marginal rate which does not exceed about 50% unless one is so rich these tax shelters are meaningless.

My impression is that the article is looking forward, not backward. I understand that the CRA does not go after tax arrears older than around 7 years. Too much work for too little gain unless the person being investigated is a really big tax cheat, like Trump. 

$100 in extra savings per year is not worth worrying about if your RRSP is worth more than $100K. As for a TFSA, the money you put into it is after tax income. The CRA has no case to apply an extra charge for a benefit since it is not losing any tax dollars.

I do not pay a fee on my RRSP nor on my TFSA. If I can get away with this so can others.