Well... Were I to speculate, I would suggest that the road was unusually narrow for the view expected by a back seat pilot in a Stearman. When he pitched up to rotate (perhaps a little underspeed), he also suffered a reduction in directional perception, so drifted left. The effort to get back on track both used up energy, and disoriented the pilot, so he tried to outclimb the wires with too little speed, and stalled over them.