Dude, I think you're far away from a lemon process based on just limp mode. If you're not suffering from fuel pump issues maybe it was just a random thing.
BTW, if it happens again, simply park on the side of the road, shut the engine down, wait a few secs then start it back up and it should disappear and you'll be back in business. Beats driving up that hill in limp mode. If it persists, however, then perhaps you do indeed have a problem.
335i E90 / Arctic / Gray / Burl Walnut / Steptronic / ZPP / ZSP / Paddles / CA / Nav / PDC / OEM Spoiler
Mods: PIAA Angel Eyes, Rear Fog Switch, Escort X50 Blue hardwire, 30% Charcoal Llumar
Installing soon: Rear Power Outlets (Happy Robot mod!)