userland is active during late shutdown or even panic?

Has anyone here noticed weird behavior where userland on can be alive and well 
during quite late shutdown phases?

First, I noticed this report on FreeBSD forums.
Initially, I didn't find it believable, but the poster provided quite strong 
evidence and details.
https://forums.freebsd.org/threads/zombie-kernel-reporting-its-own-crash-via-network.95217/

Then recently, I first hand experienced a similar thing during a normal reboot 
of a system.  Here is console output from an ssh session connected to a host 
name 'ryth':
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29759/usr/home/avg
pts/1:[0]:ryth#18:28>poweroff ; exit
Shutdown NOW!
poweroff: [pid 14930]

*** FINAL System shutdown message from root@ryth ***

System going down IMMEDIATELY

System shutdown time has arrived

[root shell exited, but user shell is still active on ryth]

28923/usr/home/avg
pts/1:[0]:ryth-18:28>tail -30 /var/log/messages
[snip]
Nov  3 18:28:25 ryth shutdown[14930]: power-down by root:
Nov  3 18:28:25 ryth ntpd[2088]: ntpd exiting on signal 15 (Terminated)
Nov  3 18:28:25 ryth upsmon[1989]: upsmon parent: read
Nov  3 18:28:25 ryth kernel: .
Nov  3 18:28:26 ryth kernel: , 1739.
Nov  3 18:28:26 ryth kernel: Waiting (max 60 seconds) for system process `vnlru' 
to stop... done
Nov  3 18:28:26 ryth kernel: Waiting (max 60 seconds) for system process 
`syncer' to stop...
Nov  3 18:28:26 ryth kernel: Syncing disks, vnodes remaining... 0
Nov  3 18:28:27 ryth kernel: 0
28924/usr/home/avg
pts/1:[0]:ryth-18:28>

[finally ssh (slogin) gets disconnected]

Connection to 192.168.0.77 closed by remote host.
Connection to 192.168.0.77 closed.
zsh: exit 255   slogin ryth
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

It was a weird feeling seeing "Syncing disks, vnodes remaining..." in messages.

-- 
Andriy Gapon