Pretty good episode, but yeah, like a lot of people here I'm kinda itching for the battle to begin already.
And seriously, how do you not notice zombies walking up on you in a forest?? Unless it's incredibly dense with trees and foliage (which the one in this episode clearly wasn't), you should be able to see them coming a mile away.
Not to mention all the sticks and branches you'd hear them stepping on along the way. Those places are so quiet you can hear every little sound that's made.