A lot of this Deus Ex Machina stuff (and I'm not necessarily picking on anyone in particular, as this seems to come up a LOT lately) boils down to "I expected the strip to happen this way and it happened another way I didn't expect so blah." A lot of people (including me, I'll add) expected Durkon to come in and save the day right of the bat with his new spell and unstoning Haley. This is a new development but isn't unwelcome to me, because now I want to see how Durkon and Elan get out of this. Just because what you were thinking was going to happen didn't happen doesn't make it a deus ex machina.
I understood that dialogue as being there to remind the readers that Nale is a spellcaster. I think the last time that was mentioned was way back in the very early strips so I get why it was repeated. Doesn't make this a deus ex machina.