The Gemara (Sanhedrin 21b-22a) records a discussion about the script of Torah scrolls (ashiri or ivri).
Many commentators look at the first opinion in the discussion and wonder if it means that the tablets were also written in ashuri or ivri script. The primary objection to the notion that they were in ivri is because the Gemara in Shabbos 104a says that the ם and ס miraculously floated in place (because all of the letters were engraved all the way through).
Now, Radbaz (responsun 883, addressing our discussion in Sanhedrin) questions the difficulty with saying that the tablets must have been written in ashuri, because the Yerushalmi (supposedly to the same chapter as Shabbos 104a) says that according to the opinion of the one who says the ancient Torahs were written in Ivri, it was the ע which floated in place (because in Ivri it looks like a closed triangle).
Radbaz answers this by saying that the ע of the second tablets floated in place, and was written in Ivri, but not the first. (For a better understanding of the setup to this question, see the Sapirstein Edition of Sanhedrin, page 22a note 22).
The question is:
I heard (from a Rabbi, although I don't know his source) that the second tablets were NOT engraved all the way through! So how could Radbaz say the miracle applied to the ע of the second tablets, if the second tablets has no such miraculous properties?