They don't believe God carved the tablets with his own fingers.
The Bible was written and rewritten by men. Each time they redid it, they left clues of the original, they kept creating a mess. So today when Bible worshipers claim God wrote all the Bible they make fools of themselves.
Look at the mess of the two different versions of the tablets:
"Why are the ten commandments in Exodus 34 different?
"The first stone tablets with the ten commandments were smashed by Moses, so God created a second set of stone tablets
that were supposed to contain the same commandments as the smashed tablets. But the actual text of the second set of commandments that follows in Exodus 34 is different from the original commandments."
Why is this second set different from the original ten commandments?
Exodus 34 (KJ21)
And the LORD said unto Moses, "
Hew thee two tablets of stone like unto the first, and I will write upon these tablets the words that were in the first tablets which thou brokest.
[...]
11Observe thou that which I command thee this day. Behold, I drive out before thee the Amorite and the Canaanite, and the Hittite and the Perizzite, and the Hivite and the Jebusite.
12Take heed to thyself, lest thou make a covenant with the inhabitants of the land whither thou goest, lest it be for a snare in the midst of thee.
13But ye shall destroy their altars, break their images, and cut down their Asherah poles.
14For thou shalt worship no other god; for the LORD, whose name is Jealous, is a jealous God,
15lest thou make a covenant with the inhabitants of the land and they go a whoring after their gods, and do sacrifice unto their gods, and one call thee and thou eat of his sacrifice,
16and thou take their daughters unto thy sons, and their daughters go a whoring after their gods, and make thy sons go a whoring after their gods.
17"Thou shalt make thee no molten gods.
18"The Feast of Unleavened Bread shalt thou keep. Seven days thou shalt eat unleavened bread, as I commanded thee, in the time of the month of Abib; for in the month of Abib thou camest out from Egypt.
19"All that openeth the womb is Mine, and every firstling among thy cattle, whether ox or sheep, that is male.
20But the firstling of an *** thou shalt redeem with a lamb; and if thou redeem him not, then shalt thou break his neck. All the firstborn of thy sons thou shalt redeem. And none shall appear before Me empty.
21"Six days thou shalt work, but on the seventh day thou shalt rest; in plowing time and in harvest thou shalt rest.
22And thou shalt observe the Feast of Weeks of the firstfruits of wheat harvest, and the Feast of Ingathering at the year's end.
23Thrice in the year shall all your menchildren appear before the Lord GOD, the God of Israel.
24For I will cast out the nations before thee and enlarge thy borders; neither shall any man desire thy land when thou shalt go up to appear before the LORD thy God thrice in the year.
25"Thou shalt not offer the blood of My sacrifice with leaven, neither shall the sacrifice of the Feast of the Passover be left until the morning.
26The first of the firstfruits of thy land thou shalt bring unto the house of the LORD thy God. Thou shalt not boil a kid in his mother's milk."
27And the LORD said unto Moses,
"Write thou these words, for according to the tenor of these words I have made a covenant with thee and with Israel."
28And he was there with the LORD forty days and forty nights; he neither ate bread nor drank water. And He wrote upon the tablets the words of the covenant, the Ten Commandments.
God isn't a mess, he didn't write the Bible, man did.