This is exactly where trust comes in. If you trust that your player of a paladin PC is sincerely trying to play an honourable and holy warrior, then let him/her play the god in question (or at least the god's attitude to their paladin). If s/he decides that s/he has wronged his/her code or god, s/he will enact the punishment (as in the actual play example in my OP).
Alternatively, if this is too much to come at, decouple the class powers from divine approval (as 4e does).
Think i got the part directed at me...
Why would the player play the god? what if two people share the same deity?
you must trust your players. you have to work out alignment with them, even if something as simple as 3 dots each on 2 lines.
Chaos-N-Law
Good-N-Evil
I would use more degrees in there of course, but that is all alignment really is. A DM should set out beforehand to explain how many spaces certain types of actions would move, and alignment should never change during a game session unless it was drastic. This allows time after the game to discus with any players what has been going on with their alignment as percieved from the DM POV, and how the players see it.
Not only does the after-session discusion help with alignements, but it helps the DM know a lot about the game that is being played, player expectations, DM gets to give expectations, and make sure the DM and PCs all got all the important stuff from the sesion rather than a drink of soda, bathroom break or something else cause a simple miss of some information.
The players must always be allowed to play as the se fit, and must always think they are doing things within their alignment. If they question there action, then maybe they realized something even the DM didnt that they did wrong, or at least did wrong in the way they wanted to play.
I always think of it as the old rules for getting lost. The players always think they are heading in the right direction. Only when they stop to ask, do they find out they have made a wrong turn. The DM shouldnt just tell them they should go left instead of right, but give them a chance to make choices for themselves, if their choices are to have any meaning.
So long as there is not interruption of game, talking is done after about potential alignment changes, and only very drastic means cause alignment changes during a sesion; alignment is real simple even when disputed.
As with the thread that spurred this one, take the player's action and figure out after the game why they thought those actions were in accordance with the PCs alignment.
The monk-paladin tried to leave things alone when he thought his job was done, but wasnt allowed to leave the refugees and go elsewhere. Anything he did was at opposition with the DM views of his alignment. I think I said there, or someone did, that when the monk-paladin got the refugees to a safer place, his "good" was satisfied, and the "law" didnt say he couldnt leave them outside the city.
Someone mentioned the 9 alignments, well 10 some would say, but i always preferred the two axis. Don't try to figure out if an action is lawful AND good, but figure out if the action is lawful OR good, and move the appropriate one or both towards neutral if need be. It is a heck of a lot easier to rationalize if something is lawful or not.
Also good and evil will always be subjective, but lawful can be too. Lawful doesnt mean following ALL laws as the evil ones wouldnt be followed, so maybe the paladin was following the laws of somewhere else. Pelor (is that the correct deity?) may likewise not view all laws as ones that should be followed, but the more important thing is the order those laws bring as opposed to chaos.
Chaos and Order are the opposing side really, never understood why it was called Lawful except maybe it just sounded better. Thinking of it as being Order rather than Law, might help many with alignment.