I've encountered both:
- Opponents denying the repair of a weapon, because it was past the point of the ASOP for that phase.
- Opponents refusing to repair their weapon, even when prompted to do so, because it was past the point of the ASOP for that phase.
My consequence is that I run down the ASOP with my finger, which slows play...
von Marwitz
Yet another good reason to adopt that house rule that shifts weapon repair from the rally phase to the fire phase, when you intend to use it. Thanks to the limits of human memory, this is often what happens in practice anyway. I have gladly allowed opponents to attempt repair out-of-sequence, indeed the practice is so widely used that across 10 tournaments I have never seen such a request denied, although I am sure that does happen.
In any case, fire phase repair attempts make more sense. The usual rally phase attempt reveals the fate of the weapon before the attacker has to make decisions about movement or fire. For example, "A ha! I see that you failed to repair your HMG in the rally phase, so I will now go ahead and move freely in your face." If, on the other hand, that attacker had to make the move decision first, and then the defender could, as part of defensive fire, make his repair attempt the game would benefit.
Anyway, I'm happy to stick with the SOP, but there is a really good case for amending the rules to shift repair attempts from rally to fire phases. And that case is so good that we often see players allowing it in practice, even if they don't label it a "house rule."