Like I said, I believe there was a workman and he was given a key by John...No breaking and entering. Happens every day!!
Once they located the worker (I'm betting he came forward), that was the end of the floorboard evidence.
That is entirely supposition, not based on any facts. Please stay with the facts.
They are not going to remove that large of a piece of the floor unless there is something there they can use as evidence. Otherwise they would just take a picture of it.