Unknown variable "Sentry"

[Lemonade]

I was on a random "My server" with 2.3.2. The lag was incredibly high like the server was on the moon. Someone took Constructor, plopped his autogun down and probably left or something. His Autogun was destroyed and I got the following error (didn't go away) :

ERROR in
action number 1
of End Step Event
for object SentryTurret:

Error in code at line 3:
   if ownerPlayer.sentry != -1 {
                  ^
at position 17: Unknown variable sentry

That's wierd IMO.