Complex sentence: Devine claimed that his speech resulted from a childhood accident in which he fell while running with a curtain rod in his mouth at the Beale Hotel in Kingman, causing the rod to pierce the roof of his mouth.
Split into simpler sentences: Devine claimed that his speech resulted from a childhood accident. He had been running with a curtain rod in his mouth at the Beale Hotel in Kingman, and, when he fell, it pierced the roof of his mouth.