He's either trying desperately to prove he's indispensable or he's sublimating something.

I'm not so sure about that. I think working miracles comes naturally to Bunter, and no further explanation is needed than that miracles needed to be worked, so he did. After all, In Clouds of Witness he not only held Peter's weight in the mud for half the night, he also managed to get up early in the morning to clean and press his clothes afterwards, and to make sure there was breakfast.