When the group is hiking up to the cave that holds Silas, they all walk at human speed, with Shane leading them at the front. There is no logical reason for this, considering that everyone in the group except Shane has supernatural powers (vampire speed, Hunter's physical ability, witch powers). They were all in a hurry to find Silas before any rival groups could, and if one of them had carried Shane, the hike would have lasted a matter of minutes.
Throughout the entire episode, no one is able to get a signal on their cell phone, nor is Shane able to receive a signal on the satellite phone, yet somehow Elena is able to send Caroline pictures of Jeremy's tattoo over the internet.