A question about the movie Percy Jackson and The Sea of Monsters

Recently, best beloved and I went to see the movie Percy Jackson and The Sea of Monsters. We did a lot of laughing and really enjoyed the show, but there was one scene that left me confused because I did not know how to interpret it.
Apparently Dionysus has offended Zeus, and every time Dionysus pours out wine, the wine turns into water. During one of the multiple times Dionysus is pouring out wine, he grabs the cup of water and says something like, "You know, the humans have a god that did the opposite." He holds up a forefinger and roars, "Now that's a God!" I get the reference to Jesus turning the water into wine at the wedding in Cana. And the gods in the movie do not seem like gods exactly, but more like powerful people with supernatural powers. And there is a lot of humor about how silly these gods are.
So here's what I don't understand: is the scene cleverly inserting a truth claim using the upraised finger that meant in the late sixties and the seventies that there is ONE God (and none of these guys are it) or is it a goofy bit of blasphemy?

I posted this question in Christian Science Fiction and Fantasy on Facebook and received these fascinating replies:

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  Kat Heckenbach I'm reading the first book, and it brings up the

question of God. The book says:

"Wait," I told Chiron. "You're telling me there's such a thing as God."
"Well, now," Chiron said. "God--capital G, God. That's a different matter altogether. We shan't deal with the metaphysical."
"Metaphysical?" But you were just talking about--"
"Ah, gods, plural, as in, great beings that control the forces of nature and human endeavors: the immortal gods of Olympus. That's a smaller matter."
"Smaller?"
"Yes, quite."
 Kat Heckenbach I also found him quoted as saying: "In Western
Civilization, we’ve always had an uneasy mix between Classical mythology and Judeo-Christian values. As a culture, we tend to believe in one God, but we also grow up steeped in these wonderful old stories about the Olympians. As long as we recognize them as stories that are part of our heritage and long-since stopped being any kind of serious religion, I don’t see the harm in learning mythology."

Rod Bennett The actual quote in the SOM movie is "I hear the

Christians have a guy who can do that trick in reverse. Now THAT'S a God." Interestingly, several of the early Church Fathers noticed this reverse parallel between Dionysius and the Cana miracle in writings from the 3rd & 4th centuries. Wonder whether the screenwriter was aware of that?