Are incapacitated heroes targets?

In another topic, Christopher said that incapacitated heroes can be infected by Plague Rat's Infection cards.  My assumption is that his point should be interpreted thusly -- when a hero gets incapacitated, you must flip them and remove all of their cards in play, but the rules say nothing about removing any villain cards that have been played against them.  So the hero will remain infected for the rest of the game.  However, this raises the following question:

If a new Infected card were drawn, could it be applied to an incapacitated hero?  Are incapacitated heroes considered targets?  The Glossary states that "any card with HP is a target", and since the hero has hp (zero hp, which is different than not ever having hp like an Ongoing or Equipment card) then a case could be made that incapacitated heroes are targets.  But this would open up a bizarro world where any time the villain targeted the hero target with the lowest hp, that would be an incapacitated hero (zero will always be the lowest), and any time the players got to choose who received an effect like Infection, they could pin it on the incapacitated guy where it would do the least harm.

We've always assumed that incapacitated heroes stop being considered targets as soon as they're flipped, but I can't find any support for that assumption.  Discuss.

First, incapacitated heroes do not have zero HP, they have no HP stat.  If you look at the cards, the active side has HP on the card, and the incapacitated side has no HP on the card.  This is exactly the same for The Operative and the various cards of The Ennead.  Once flipped to the incapacitated side, the cards are no longer targets (or, they are targets on one side of the card, not on the other).

Second, you cannot play infection on an incapacitated hero.  The card states that it must be played on an active hero (an active hero is a hero that is not incapacitated).  Obviously an infection card can be in play on an incapacitated hero, as Christopher has suggested, it simply cannot start off that way.

Third, an infection card is played on an active hero and "targets" a hero card, not a hero target.  Thus why it can still be in play on an incapacitated hero.

Hmmmm, so are we saying that targets that are in play but have 0 HP are the lowest HP targets for those effects? (e.g. Muninn and Huginn)

When a target is reduced to zero or fewer HP, it is destroyed.  However, targets that are reduced to zero or fewer HP which are also indestructable are not destroyed (as has been mentioned in Rook City playtesting).  Also, I do not believe HP can remain below zero (I may be mistaken, as it's never been mentioned before) so an indestructable Muninn and Huginn would have zero HP.  As zero would almost always be lower than any other target's HP (at best, it could tie other indestructable targets), a zero HP target would be the target with the lowest HP.  Once the indestructable status is removed, they would be immediately destroyed, obviously.

Of course, if an indestructable target can have fewer than zero HP, that would make things more interesting (and complicated, with more book keeping).