[quote=@Inkarnate]
[hider=My Hider]
Joel also acts entirely out of character to get to the spot where he could get ambushed and murdered in such an unconvincing way.
[/hider][/quote]
[hider=spoilers]
It's because he got comfortable after living in Jackson for several years. Plus, Abby helped him and Tommy out while a horde was on their asses. And the horde didn't give them much time to question this stranger unless they wanted to be eaten. 
[/hider]