While it is true that that is traveling, it is not because of 4-44-3a, but rather part c which specifically states that action is illegal.
There is no such specific statement for a fumble.
If I were to apply the same logic you used here, "The restrictions on what a player may do after lifting his pivot foot are explicit,..." to 4-44-3c, then I would point out that this rule is also explicit and it only forbids starting a dribble after lifting the pivot foot. It does not say that the pivot foot may not be lifted before the ball is released when fumbled!
