I have searched for this question in askhistorians, and there are several questions about ancient civilizations (namely Chinese) finding dinosaur bones and using them in some way.
But my question is: did early cavemen ever find dinosaur bones, and use them as some kind of tools? Or was it impossible for those early humans to find these bones in the first place since they were buried too deep?
Dinosaur fossils are frequently found on the surface, so anything is possible. Whether any archaeological evidence of early human use of these fossils exists is another question - and it is a question that necessarily predates writing (and therefore history!). You might be better off asking /r/askanthropology.
I've worked on both early hominids and the history of fossil discovery, and I can't think of anything here. History tends to deal with humanity after the advent of writing, and indeed it sounds as though you've found some of the scholarship dealing with early fossil hunters. We have good evidence not only from East Asia, but also from the western classical world that prehistoric fossils were found with some regularity--though of course they weren't concieved of as such. The idea of the "prehistoric" wouldn't be invented until almost two millennia later.
You could always try asking r/askanthropology.
I do want to correct one misapprehension, though: dinosaur fossils, like many fossils, are often found quite close to the surface in places where superseding strata have been eroded.
I do like the visual of H. erectus smashing up a skeleton, 2001-style, with a massive dinosaur femur, though!