I'm not necessarily out to defend the behaviour of this person - I think they were pretty callous, and some of the other practices also seem pretty horrendous but I also think some of the offence readers of this article may take come from projecting our own personal views onto the behaviour of others, ignorant of the different origins and cultural contexts of the offender.
When slurs such as referring to people as monkeys are used by the Chinese, they are not steeped with the kind of hatred and historical context when wielded by someone from the West.
---That doesn't make it any less hurtful or insensitive---
That said, it also doesn't necessarily carry the same intent as it may outside of China. Comparison with animals is far more normalized and entrenched in culture: for instance, everyone is assigned a zodiac by their birth month and the Monkey King is a household mythological hero.