I am sure they thought themselves amusing. They didn't feel ashamed at their boorish behavior and how it infringed on the enjoyment of other people. They didn't think how being drunk and high might endanger other people. They were thoughtless, and I would guess this wasn't the first time they had behaved in such a manner. I would guess zoos weren't the only place they felt free to tease the animals. Would they have also thought it funny to tease a dog like Lucy? Why not? What was to stop them? Like Lucy, Tatiana was killed when she reacted as one would expect.
Yet perhaps Tatiana was not only a victim of her own instincts, but also the hero. She prevented these men from getting back in their car, getting drunker, driving drunk, and perhaps ruining the day and even the life of another person or animal.