So... To stop these useless reminders, is "goddidit" always an already presumed option when discussing evolution related topics?
Not specifically. Actually, in any philosophical debate - any conceivable and unfalsified hypothesis is a presumed option, and Goddidit - just as with any unfalsifiable hypothesis is unfalsified.
However, we don't have to limit ourselves to god, we can philosophically have any entity, concscious or otherwise be the cause of 'it' - assuming that this entity is not ruled out by whatever system of philosophy we are using.
When we are using science as our system, then obviously the Abrahamic God is out since under the philosophy of science the Abrahamic God is unfalsifiable and unfalsifiable things are ruled out as explanations in science.
In theology unfalsfiable things are not ruled out, they are often ruled very much in (belief in things unseen...).
So in short - it depends. On a purely philosophical level - Goddidit is an option. When we start discussing particular philosophies, Goddidit may or may not be a presumed option. In science God is an extraneous entity (and is thus unparsimonious), and unfalsifiable so is not a presumed option until such time as God becomes parsimonious and falsifiable.
Since the conversation happened in the science forums, god is an unnecessary explanation and is not a presumed option - this option has to be supported with evidence. Theories are all about explaining things. The hows. So if god did it, the scientific question to ask is 'How?'.