>>544638830
It's all just conjecture, there's too little to actually go on. All we know is that Gregor was revered then, loathed afterwards. And we don't know why or how.
The Soldiers thinks he deserted them, but then he also rebukes with a "I was thrown out too, you know." so it's all around unreliable and undetermined information as of yet. As it turns out, Gregor isn't all that stable either.