Exactly this - a friend, local to us currently building had a very similar issue these past few months. The neighbour complained that he believed the standalone garage ridge height was higher than it should have been given the plans. Planning came out and were satisfied it wasn't BUT found the garage footprint was actually 1 metre further to the Left / Right than it should have been.
There was a genuine possibiilty that the garage had to be taken down and "shifted" back a metre - Thankfully, for them, the matter was resolved by a further "amendment" to the plans and a much reduced cost - it caused 3 months of delays mind
So, as @Nod says, you should be OK providing your neighbour is either on board or unaware!