[Samba] deadtime/keepalive not working as expected

[Ed Siefker]

My expectations are probably wrong, but I had to manually kill a process
to unlock a file when I think it should have killed itself.

I have deadtime set to 15 and keepalive at default (300).  I opened a file on
my server in Excel, then shut down the machine.  Hours later someone
tells me the file is locked.

Shouldn't keepalive have detected that the machine was off in 5 minutes?
Shouldn't deadtime have disconnected the process and unlocked the file
15 minutes later?  Do I misunderstand what is going on?  Thanks
-Ed