Why is Windows calling one of the files "newer" while their timestamps are the same?
Timestamps in the NTFS file system have a resolution of 100 nanoseconds (0.0000001 s). Even if the properties dialog shows the same rounded value, it could still be that the files were created e.g. within tenths of a second from each other.
(Most file systems measure times in μs or ns. FAT32 is a bit of a relic and rounds timestamps to 2 seconds.)
Try one of the following methods to compare the full timestamps:
wmic datafile where name="c:\\foo\\bar.txt" get lastmodified
PowerShell:
(Get-ChildItem c:\foo\bar.txt).LastWriteTime.ToString("o")