The family tax cut is designed as notional income splitting, if you will. Both spouses have to reallocate their income then split the taxable income. Some of the credits may have been transferred between members before that calculation, like the age credit, the pension income credit, and also education credits. To do the proper calculation, these credits are taken from the return of the high-income spouse and are put back in the return of the lower-income spouse to avoid some potential double counting in the value of these credits.
When this was initially designed this drafting error happened. One of these credits, the education credit, which includes tuition, education, and textbook credits, the way these credits are transferred between spouses, the impossibility of double counting is already in the calculation. We should not have removed this specific credit in the calculation of the family tax credit. We're readjusting that correctly.
With respect to the question as to how much families could be penalized, first of all, this would apply only in a case where there's a transfer of education credits between spouses and the maximum amount would be $750, which is equivalent to 15% of $5,000, the maximum transferrable amount of credits between spouses.