He probably would've. It would certainly be a good idea, since even the sheriff might not fare too well against multiple outlaws.
Anyway, anybody not inside the shelter is pretty much confirmed as an outlaw, since deputies would've said something.
You say that like anyone has any reason to believe anything anyone else says...
It's not about belief. Let's break it down.
We have
a Sheriff, a dead Deputy, a dead Outlaw, and three unknowns.Now, not far long into the game, Tiruin and Lukeinator hid in the ammo cache. Tiruin hiding their was certainly the correct move for a Deputy, and probably a good choice for an Outlaw too. It would be a terribly stupid thing to do as the Renegade, though.
Not long after, I left my hiding place and went in there, as I was unsure of Tiruin's alignment due to my apparent inability to read. I was afraid that Tiruin would turn out to be an outlaw be able to kill Lukeinator through luck or shenanigans. Now, since we only have one person outside, and one deputy remaining,
it should be immediately obvious to the only remaining outsider whether there's a deputy inside or not. If they were the deputy, they would warn Lukeinator, since in a 2v1 even the sheriff would probably lose; there's a chance they might be trying for a gambit, but I feel pretty comfortable in my assumption that they're an outlaw.
Of course, I
know they're an outlaw since I'm the deputy; unfortunately, this makes this all confirmation bias. However, I think my logic is sound.