I saw a Tahoe yesterday pulling a 30-ish footer. No WDH or sway, nose pointed at the sky. Now...I pull a similar sized trailer with a Tahoe BUT I've got the HD stuff with 3.42 gears and a 8500 lb tow rating and upgraded the tires on back. If, like I suspect, his was a standard model with 3.08 gears and a 5500 lb tow rating and that trailer weighs what mine does...he's several thousand pounds over tow rating and several hundred pounds over his hitch rating..probably without brake controller. If so, he's insane or just plain ignorant.
2012 Chevy Tahoe LTZ - HD tow package
2017 Rockwood 2703WS Emerald Edition