I'd say it was a bad experiment since it didn't reflect the indoor environment. Feeling confined in a shop may produce different results than having blue sky above you while walking among some shelves. I'd say it didn't adequately reflect the actual environment, and is therefore a flawed experiment 😁
Discussion
Agreed. At the same time, most animals don't want to touch things, especially unfamiliar things. They'll slip through, seemingly impossible, gaps to avoid contact.