What's the problem? In the first case it's simply a matter of the DM knowing the rules and the problem is solved. ...
In the second case - who cares if the PC is blasting stuff right and left? First of all it's a dungeon. Secondly, why is it the player's fault if his character gets unlimited blasts?
Assume some sort of hypothetical "real-life" situation - what are some negative consequences of walking into hostile territory and blasting away and every object in sight? I'm sure you can add to this list:
(1) You make lots of noise and attract monsters
(2) The statue may contain a lever that opens a secret door, and now you've just destroyed it.
(3) The statue may contain, or be, treasure, and now you've just destroyed it
(4) The statue may be a petrified ally, and now he's had his head blown off
...Expect smart players to solve problems.