http://decision.tcc-cci.gc.ca/tcc-cci/decisions/en/item/71769/index.do 
Stamatopoulos v. The Queen (September 29, 2014 – 2014 TCC 169) was a decision on a motion to add one paragraph to the Notice of Appeal on the eve of trial:
[1] Before the hearing of the appeal began, the appellant presented an oral motion for leave of the Court to file an amended amended notice of appeal.
[2] The respondent is not contesting the amendments the appellant identified in his amended amended notice of appeal, except for the addition of paragraph 8.1 of the amended amended notice of appeal, which states the following:
[translation]
Every month and at the time his GST/QST return was filed, the appellant submitted form VDZ-350.49-V, “Subcontracting Expenses Information Return: Clothing Industry”, to the ARQ as required by the ARQ, and identified all the subcontractors with which he did business.
[3] According to the respondent, form VDZ-350.49-V, Subcontracting Expenses Information Return: Clothing Industry (the form) must be submitted with the Quebec sales tax (QST) return and not with the goods and services tax (GST) return. Thus, for GST purposes, this form is not relevant. Consequently, the respondent argued that I must not allow this amendment.
The court concluded that it was possible that the Quebec tax authorities could have referred to this form for GST purposes (they administer the GST in Quebec) and accordingly permitted the amendment:
[14] Under the Tax Administration Act, the ARQ may, for GST purposes, use the information it obtained in the administration of the QST. The converse is also true: as a consequence of the Canada-Quebec Agreement the ARQ is likewise authorized, under subsection 295(5) of the Excise Tax Act, to communicate for QST purposes information it obtained in the administration of the GST.
[15] The question of whether the information on the forms was or was not used for GST purposes in the present case is an issue the Court will determine at the hearing. As a result, I am of the view that at this stage of the proceedings it would be unwise to conclude that the forms identifying the subcontractors are not relevant for GST purposes.
However because of the lateness of the application costs were awarded against the appellant:
[17] That being said, the motion for amendment could have been filed well before the morning of the hearing. As a result, costs of $700 are awarded to the respondent [regardless of the outcome of the appeal].