I think Sasuke had two things at the moment Naruto and Sakura found him:
1 - Orochimaru's cursed seal that gave him an urge to kill, that's why he tried to kill Naruto until he spoke with the kyubi (I guess the seal in Sasuke worked a bit like the kyubi in Naruto: when something does make you angry, it makes you hate --> he was not unfeeling after seeing Team Kakashi)
2 - he was really mad at the idea that he could not do as he wanted, that someone like Naruto and Sakura wanted to order him to go back to Konoha. He's too independent and unwilling to be given orders.