I've finished playing GAG late last night. I had reached this spot actually:
but that was THE END, as I later saw thanks to Jan (thank you!).
Too bad GAG wan't play till the VERY end, there are a few nice screenshots in the last cutscene I would like to take and I don't want to do it with YT.
P.S. I still believe & hope that message is just another GAG's prank. Looking for a way to bypass it.