Don't you need more states, or an invalid state state to account for bounces?
Ex: 00 -> 10 -> 00 is interpreted as 0 -> 3 -> 0, or -1 transition then a +1 transition.
01 -> 11 -> 01 is interpreted as 1 -> 2 -> 1, or +1 followed by a -1 transition.
All possible combinations of bounces (00 -> 01 -> 00, 00 -> 10 -> 00, 01 -> 11 -> 01, 01 -> 00 -> 01, etc. etc.) have this +1 / -1 or -1/+1 property.