STT’s notion of time is so messy… You can define a unit of time as you like. So, STT could say that a very fundamental unit of time is the time it took for the universe to “transit” from its “non-existence” to its existence. Naturally, you can always divide whatever time interval you might conceive. So, let’s divide STT’s fundamental unit of time into two equal sub-intervals, and let’s ask STT: “What was the ‘state of existence’ of the universe by the end of the first sub-interval?”, and there are only two possible answers: a) “non-existence” or b) “existence” (though, as usual, STT could evade the question with the first thing that comes to his mind, thinking that it is a brilliant answer: “I don’t know, I was not there!”).
If one answers that the state of existence after the first interval was “non-existence”, then the act of creation had to happen during the second sub-interval. If, on the other hand, one responds that the state of existence after the first interval was “existence” already, then the act of creation had to happen during the first sub-interval. Therefore, in any case the time interval which was defined as the very fundamental unit of time, is not the very fundamental unit of time; which is a contradiction. Therefore, STT’s argument is unsound (so, his conclusion is false).