I really can't see a skull cast in that stone ... but, the possibility is remotely possible, I guess ?
If the stone is scoria, a volcanic rock similar to pumice, ... then we have to remember pompeii ... fossil casts up the wazoo from volcanic activity. So, the process is possible.
I looked up "Why don't we have primates in North America", and a couple things came up.
I guess we did have them, like 50 million years ago ... Florida and the Caribbean were mentioned.
They said that there was a warm period that occurred and that fossilized palm trees have been found in Alaska.
During a warm period such as that, if the primates had a short time to survive in Florida, then it might be possible that they reached up into Georgia.
New info for me.
IF a very experienced geologist examined this and saw things that we can't see in the pictures ... Well, I'm still very skeptical, but it is not ENTIRELY impossible that something like this could occur.
It would take a very close examination, coupled with a few more studies and opinions, but I don't think we can rule it out, entirely.
I don't know ... I'd love to hear exactly what the geologist saw, and what he based his opinion on.