I tried saving him, cleared the whole way from the main gateway out, and he runs in the opposite direction and takes an arrow to the spine for his trouble.
In this run, I refused to reload to change the results of my actions, so this was actually pretty visceral. I felt for his family, even though I high-tailed it all the way to some small town, where I was challenged to a drinking contest... But that's another story.
The first time I went to Solitude, I tried to save him. I ended up being chased all throughout Solitude by an army of guards and a headsman. I eventually escaped, but I don't believe I'm welcome there anymore.
First time I saw him die I wondered "why did this idiot even open the gates ?!, wheres loyalty to your KING over the guy who killed him respected Nord Jarl or not. I know he supported the stormcloaks and all but his JOB was a guard of Solitude, if he loved the stormcloaks and their cause so much he should have left to Windhelm or a city that was supporting the stormcloaks not stayed a guard in the city that is the capital of the province and Imperial HQ of Skyrim.
"Always two there are, a master and an apprentice"