We used to have substantial problems with rule debates... They got really ugly. Mostly the fights were between me (the DM at the time) and this 'rules revisionist' guy who kept at me to house rule things in his favor. I didn't help much when I rolled out a house rule mid game a few times to thwart his abuse of loopholes. Oh the wailing!
It was not a good role playing environment...
Another guy DM'd for a while. Not so many fights (because as a player, I just didn't get drawn into them), but the DM was a softy and let rule revisionist guy run roughshod all over him. Even allowing a custom base class... There were problems...
Things Got MUCH worse when the rules revisionist guy DM'd. Mechanics changed from session to session or even during the session. Seemingly arbitrarily. Not occasionally. Every. Single. Session. And they were not 'good' revisions... I confess that I led many a charge against these percieved abuses of DM authority... Things devolved to the point where the group almost dissolved. He will not be allowed to DM again. In fact we only recently agreed to let him play again...
So, when I took over as DM again last April (and oh yes, I'm due for a break

), I mandated two Table Rules (conditional to me DMing for them):
1. No 'driving' of other people's characters. Use free actions to have YOUR character 'ask' another character for something or suggest a course of action? Sure. Even encouraged. But Players may not make pointed suggestions to players. Certainly not 'orders' (which used to happen - "do this, heal that, do this other thing! Why not? Are you stupid?!").
Coaching newbies is permitted to a point - but typically I do it (as DM) by pointing out a selection of options rather than advocating one in particular.
2. NO Rules debates at the table. NONE.
- We play it as it lays in the Rules as Written or in ESTABLISHED House Rules.
- House Rules can only be established between sessions (there's a notification and documentation process)
- In case of gray area (no applicable rule can be found in a reasonable time) the DM shall make an Interim Ruling (which shall tend to favor the PLAYER). This shall be revisited beteen sessions and a clarification or House Rule established prior to play resuming
No 'at table debates' (fights) have occurred since Rule 2 was established. I once again have firm control at the table, and the environment is fairly healthy. There is also a fair amount of 'buy in' from the players and the other DM (the softie) - who will keep them when he takes over. Soon!
'Rules Revisionist' guy is on probation and things are working out so far. Except for his tendency to tinker (badly) and a pronounced lack of attention span, he's a fun player to have around...
A'Mal