Of course it’s a coincidence. Oh, you mean because of the number 613? Well, that would have significance if there were 613 million mitzvos. But, to the best of my knowledge, there are only 1/1,000,000 that number.
A person does not stub his pinky, unless it was decreed from heaven. There is no such thing as coincidence and everything is decreed from Heaven.(except your Yirat Shamayim.) Everything that happens in this world is for Bnai Yisrael!!