Should be considered a triple resistance.
Don't know whether GamePress goofed or Niantic screwed up and made immunity plus resistance only count as a double resistance. Both seem possible. ;-)
GamePress also has Charizard as double resistant to ground, when the immunity and weakness should balance out to a single resistance.
These should all be single resistance:
-Ground vs Charizard, Zubat, Golbat, Aerodactyl, Zapdos, Moltress, Crobat, Skarmory, Ho-oh
-Ghost vs Girafarig
-Electric vs Wooper, Quagsire, Gligar
