...and how did he get out of the hospital so easily without notice? I hope the writers didn't just cut corners here.

He was trying to get a flight out of NYC and to the middle of the desert, so I'm guessing he was talking to an airline booking agent. As far as getting out of the hospital, it happens on TV all the time. Security at television hospitals is lax. Don't let it vex you too much.

Well Mama Petrelli saw him when he left. Plus he's an adult so the hospital couldnt stop him from leaving. He can sign himself out against medical advice.

I doubt it was without notice. From the way his mom described it, I got the impression it was something of a scene. They wouldn't have forced him to stay if he was set on leaving.

He wasn't a criminal suspect to be restrained or anything. Patients can leave if they want.

Mama Petrelli's character seems to be taking a bit of a twist too. I think she knows more about the powers than she lets on.

As for his phone call, it sounded like he was trying to book travel arrangements.

I just assumed that Peter had gone invisible without noticing before he left the hospital. You know, he wakes up, freaks out, his mom leaves the room to get a nurse or something, and then poof! He's gone. Enabling him to leave the hospital without any trouble at all.

I suppose that might depend on how far Claude was from the hospital and what the range on Peter's power is like (especially now that it seems to be growing), but that's what I thought.