Better for a person to do it in game to see, but heres a couple logs.
Code:
[Mon Aug 31 07:56:48 2015] Gage tells you, 'Welcome to my bank!'
[Mon Aug 31 07:56:48 2015] You are no longer hidden.
[Mon Aug 31 07:56:48 2015] You stop sneaking.
[Mon Aug 31 07:56:48 2015] You begin to hide...
[Mon Aug 31 07:56:48 2015] You have hidden yourself from view.
[Mon Aug 31 07:59:04 2015] Gage tells you, 'Come back soon!'
[Mon Aug 31 07:59:30 2015] You begin to sneak...
[Mon Aug 31 07:59:30 2015] You are as quiet as a herd of running elephants.
[Mon Aug 31 07:59:41 2015] You begin to sneak...
[Mon Aug 31 07:59:41 2015] You are as quiet as a cat stalking its prey.
Code:
[Mon Aug 31 07:55:52 2015] Perkins Doughbeard tells you, 'That'll be 15 platinum 3 gold 3 silver 7 copper for the Crystallized Pumice.'
[Mon Aug 31 07:56:18 2015] Perkins Doughbeard tells you, 'I'll give you 2 platinum 2 gold 4 silver 2 copper for the Giant Scalemail Gloves.'
[Mon Aug 31 07:56:20 2015] You receive 2 platinum 2 gold 4 silver 2 copper from Perkins Doughbeard for the Giant Scalemail Gloves(s).
[Mon Aug 31 07:56:28 2015] You begin to sneak...
[Mon Aug 31 07:56:28 2015] You are as quiet as a herd of running elephants.
[Mon Aug 31 07:56:39 2015] You begin to sneak...
[Mon Aug 31 07:56:39 2015] You are as quiet as a cat stalking its prey.
Banker is easier since it gives you a message saying welcome/goodbye etc. but vendor same thing. My new log doesn't have an example of sneaking behind a vendor multiple times to show 100% fail rate despite good or bad faction. Will post it up tomorrow if if matters. Really if it is a bug, its just inconvenient waiting on the sneak repop timer twice especially if you are in a rush. But meh i dunno, pretty trivial bug compared to some of the others people report.