Why not? A gene can be turned off and be turned on again by a mutation. Nothing, in principle, prevents a tiger salamander gene to be inactivated but nevertheless inherited and then mutate or find itself in a specific genetic environment that allows for its phenotypical expression.
If you´ve ever heard of atavisms, they are a very nice example of this kind of phenomenon. They correspond to genes or clusters of genes that are normally inactivated or regulated to be expressed to a specific degree (or which are expressed up to a point and then overriden later on), but which randomly mutate and reactivate or modify their degree of expression producing things like 4 limbs in dolphins, tails in humans, teeth in chickens...
Anyway, there´s no way of knowing if your animal´s trait is tiger salamander inherited or completely novel, just by looking at them. I just thought it was enough of a striking similarity to raise the question.