On windows, the inodes as reported in the ino field of the array produced by 'file stat' seem to be limited to a 16bit value.
The result is that many files end up sharing an inode as far as Tcl is concerned.
This can result in 'file rename -force' silently failing to perform the operation.
Such a clash is in general highly intermittent, but can in certain circumstances occur repeatedly in a particular folder.
(Renaming a file into place over an existing file is a mechanism that is supposed to increase data safety by not having the final data file being directly opened for writing. The effect of the duplicate inodes is that this problem may go undetected for a long time, and silently corrupt data)
I suspect (but haven't been able to verify) that this may occasionally have other strange effects during file creation using Open. I have noticed a situation in a folder where Tcl is writing files where 2 files appear to have not only the same inode, but the same name (including capitalisation).