Did you have the downhaul pulled on hard? If so, this will bend the mast and effectively make it shorter.
As far as the rigging stretching, I'm sure it can happen, but it would take place after the first few times you sailed the boat and then it would stop. It would also be a relatively small amount (maybe a one hole adjustment necessary in the chain plates).
So if your shrouds are well used or if something changed by a couple inches, then I would definitely look around to make sure everything is OK as this would not be normal stretch. Make sure all the hull fittings are secure and that the nicopress fittings haven't moved.