The DN handling only allows OU and DC, but for instance the default Computers location is not an OU, but a CN:
CN=Computers,DC=EXAMPLE,DC=COM

https://msdn.microsoft.com/en-us/library/aa366101%28v=vs.85%29.aspx?f=255&MSPPError=-2147217396

Let's pass in the raw createcomputer string into authpolicy and leave the parsing to it (it just needs to figure out the machine domain).