In order to reproduce the bug, you have got to build the setup_improvements branch by Hbelusca and mount it on a VM. When ReactOS has finished installing, do another installation again but at this time keep the FAT filesystem without formatting.
You'll see ChkDsk failing at checking the disk with status 0xc0000032. Oddly, you can still continue the setup installation even though ChkDsk failed its operation. As usual, I couldn't be able to provide a backtrace, ReactOS simply doesn't want to break into debugger even if you force it to do so. So please don't ask me for this!
Interestingly, PuTTY output some weird VfatPrint lines during disk check. I'm not sure what do they mean. The Console output a shitton of those.