After finishing the puzzle, beating the elite four and so on, I have my Ho-Oh and went to the Ruins of Alph to get the Life Orb. But I wasn't exactly sure what I was doing.

I solved the omanyte puzzle, thinking that this would activate the secret room, instead I fell through with no Life Orb and the other items on the other side.
Is there a way to undo this?

Thanks,
nikiera