Complex sentence: Peter (angry he was shot by Joe) and Quagmire (upset he wasn't the one who shot Peter) are dissatisfied, yet while Peter argues how everyone will settle their differences, Quagmire shoots Peter in the head, making the score even.
Split into simpler sentences: Peter (angry he was shot by Joe) and Quagmire (upset he wasn't the one who shot Peter) are dissatisfied. While Peter argues how everyone will settle their differences, Quagmire shoots Peter in the head making the score even.