If that indeed happened then the safety has to be out of adjustment. The reasons I say that is because...

1. You shouldn't be able to engage the safety into position 1 or 2 without the rifle being cocked (cocks on opening).
2. Once the bolt is lifted to cock the firing pin (bolt up but no rearward movement) you should be able to engage the safety into position 1 or 2.
3. Opening/closing the bolt any number of times with the rifle cocked and the safety in position 2 will not decock the firing pin.
4. Going from position 1 or 2 to position 3 at any time and pulling the trigger will fire the rifle as it should.

Are you sure you cycled a live round back into the chamber once you got up into your high chair? Wouldn't be the first time that minor oversight bit a hunter in the bum.