Thanks for that! The relevant text in section 1.2 is:
A minor malfunction is any incident without external cause which deviates from the normal course of gameplay, without directly causing a player’s loss of turn and without providing any player a significant advantage over others.
The key phrase here is "… without providing any player a significant advantage…". In other words, what happened to Robert is not a minor malfunction. (Having two balls instead of one does indeed provide a significant advantage, but the rule says a minor malfunction is a malfunction that does not provide a significant advantage.)
Section 1.2 does not apply, period.
In section 1.6, we have:
Any malfunction which provides at least one player with a significant advantage over any other player competing on that machine is known as a beneficial malfunction. Tournament officials shall determine what constitutes a significant advantage.
We can probably agree that having two balls in play when there would normally be only one ball is a "significant advantage"
Immediately below that, we find:
Any beneficial malfunction which results in a player being able to continue play of a ball that normally should have ended is normally allowed once per game. Examples of this would include an unexpected software ball save […]
And, in section 3.7:
In the event that a drained ball bounces back into play without deliberate player action, such as in the case of a “lazarus”, this is considered the mechanical nature of pinball and the ball may be played.
I think there is absolutely no doubt that what Robert experienced was a lazarus.
We have two rules that explicitly state that it is OK to have a beneficial malfunction once per game, and that a lazarus is perfectly normal: "play on".
And I am still short of a rule that would require Robert to drain one of his two balls (section 1.2 is not applicable).
If the intent of the rules is to force Robert to drain one of the balls, the rules have a problem: there is no rule that would require dropping a ball, and there are two rules that allow playing on. (Neither rule mentions anything about the number of balls.)
If the IFPA wants to fix the rules to force dropping the extra ball, the rule about the lazarus is problematic. It says "a lazarus is OK", but what people here have been arguing is that "a lazarus is OK, except when it's not". Well, which is it?
IMO, Robert should have been allowed to continue play with both balls, and the TD made the wrong decision according to the rules as they currently stand. (If someone can point me to a rule that says otherwise, I'd love to see it!)
One other thing: the rules frequently use "which" where they mean "that". Someone needs to go on a "which hunt" because, as is, the grammar is wrong in many places.