Hit a weird situation.
I gave Zane the picture of George McFly. He started to draw the picture, then said to come back later. So, I left the speakeasy and returned.
Now, he has no chat options for me to get the finished drawing, I don't have the drawing in my inventory, and if I try to show him the George photo again Marty says "I don't need ANOTHER picture."
Did I just hit a gamebreaking bug, or am I missing something?