Normally verbs such as 'finish/stop' denote something punctual it has no duration However, they can also denote the process of coming to an end, in which case the progressive form is possible, Your first sentence works if, for example, a mother has told a child to stop what she is doing, and the child has kept responding, 'OK, Mum. Nearly there, I just need another minute'. An hour later, the mother might utter you words.
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