Citation needed. I have read the primary ruling on this[1], and I don't recall anything of the sort.
As the Court notes:
> Although, during the drafting of [Article 50 TEU], amendments had been proposed [...] to avoid the risk of abuse during the withdrawal procedure [...], those amendments were all rejected on the ground, expressly set out in the comments on the draft, that the voluntary and unilateral nature of the withdrawal decision should be ensured.
[1] http://curia.europa.eu/juris/document/document.jsf?text=&doc...