This is precisely what I'm looking for too. All critiques of Hancock I can find with my feeble googling skills seem to be focused on unimportant stuff such as encouraging uses of psychedelics and accusations of racism.
But what's far, far more important, is debunking evidences like rock painting dating, geoglyphs dating. That thing on Rapa Nui about statues being more-than-half buried seemed really intriguing. The speculation he makes about why that might be so (spoiler alert: that famous lost civilization being there first) seemed interesting to me. Is there a specific debunking of that somewhere?
I'd also be interested in specific debunking of his theory that incas didn't have the capabilities to do some of the rock walls they've made. You know, with heated rocks and all. That seemed interesting too.