In 2008, he did not lose the confidence of the House, but a confidence vote was looming. There was quite a debate among the experts. It was traditionally held that the prime minister could not seek prorogation with a confidence vote pending. Some argued the opposite, meaning, that the prime minister had full freedom to request prorogation and that the request was granted automatically.
We are saying that it isn't automatic. The proof is that the then governor general consulted extensively; she imposed conditions and exercised her power of reservation. She accepted the prime minister's advice, not because she was bound by it, but because she was exercising her power of reservation. Had she denied the request, it would have meant that she had lost confidence in the prime minister and he would have had to resign.