I don't know if sw2wolf will see any differences, since shutdown -h calls halt(8) anyway.
This is interesting:
Code:
inteldrm0: gpu hung!
I wonder what time it was produced? Was it during the shutdown procedure, or at another time? If during normal operations (multiuser) it should have been captured by syslogd(8) and would have appeared in /var/log/messages with a time stamp. If during shutdown, syslogd may have already been halted.