You are still incorrect. Just checked this in cheat mod with Soviet and German howitzer.
Howitzers can be killed by targeting the gun with tanks (aka just right click on it). When it happens the gun and all crew die as they did before if the gun health falls to 0. Protection of gun by having crew does not apply to this artillery. Said another way, having crew around a gun does not help the gun survive.
Having decrewed guns proceeds as normal (as you would expect) with gun being destroyed when health falls to zero. Please upload a replay of gun going to 0 and surviving. The only thing I can think is that the CmdTank did something weird.
I see what you did with the first part of your comment. Since the question is insincere I will answer it only briefly. Targeting, in the case of artillery, is based on the players ability to drop the maximum amount of damage on an area since you cannot directly select a unit to hit.
It was an insincere question because you acted like I didn't know how to target the gun. And yes I have had guns refuse to die despite the health of the gun being at 0 and the crew still being alive. Have you been using explosive or ballistic weapons to test? Are you using bombing strikes or just tanks?
Also recrewed weapons are weird, for instance they often keep the old vet (because it applies to the weapon ~just relic things~ ) and no longer get received accuracy while crewed.
I love that commanders that haven't seen the light of day for almost 2 years are starting to see some time in the spotlight,
They got a triple buff. Soviet stock army was made better, ~some~ call in's were killed or pushed back, and they just got a raw direct buff. Unfortunately this combined means matches often just turn into point and click adventures with players just insta countering or getting raped or having endless artillery duels that nobody wins.