His terminal velocity did not actually increase (It's not a variable, it's fixed for a given body shape and orientation). He was constantly accelerating at 9.8m/s^2 (actual "free fall", FWIW) until he hit thick enough air to slow him down. (60,000 ft ?) Then, he was actually going faster than what the terminal velocity would be if he had experienced constant air resistance in a fall to that point. Wiki says, in clearer words than mine, "An object moving downward with greater than terminal velocity (for example because it was thrown downwards or it fell from a thinner part of the atmosphere or it changed shape) will slow down until it reaches terminal velocity." It is actually possible that he did not reach terminal velocity, but we don't know that yet.
