He was probably frustrated... sexually
Geese are really couple-esque. They bond pretty much for life, like penguins... and "most" of us
No to be sappy but they look for a "soulmate" very early on too. If they lose them, it's devastating to them.
I had a couple few years ago, they were 2 years old. The male got snatched by a bobcat. My girl was a mess and never recovered. She would use the dog door in the kitchen as soon as she would hear us in the morning and wouldn't want to get out. She would hang out with my son all day. Eventually, she stopped eating...
Bottom line, guarding Gs are great, just get him a good gal too