In 2010, authorities issued an ultimatum to the owner of Sammy's Kitchen, the steakhouse where the cow had been hanging for three decades, to take it down or face a fine of up to HK$200,000 ($25,000) and a year in jail.
Yau, a curator for Hong Kong's Heritage Museum before taking up post at the URA, is sorry to see the cow go, but says: "Life has to move on. Today's design is tomorrow's history."
Perhaps the biggest enemies of neon are its own idiosyncrasies.
The lights are tricky and expensive to make, requiring a neon tube-bending technician and, for something like the neon cow, a budget of HK$250,000 ($32,225).
Plus, that classic neon sign buzzing sound gets on some people's nerves.
The city's streets continue to be bathed in fluorescence -- so much so that it's considered the most light-polluted place in the world.
But these days, Hong Kong business owners who want their brand name up in lights opt for cheaper, energy efficient LEDs that lack the whimsy and extravagance of handmade neon.
A push from mainland China to use LEDs has also dimmed Hong Kong's love of neon.
"Many cities in China no longer support neon signage and this inevitably affects Hong Kong's businesses," says Tam.
Since LED light is harsher than the soft glow of neon, it's a trend that has worsened Hong Kong's light pollution.
It also creates other environmental issues since LEDs, unlike neon, aren't normally repaired or reused.resurrects
But the neon lights aren't going out for good.
"It's fairly safe to say neon's heyday is over and not coming back," says Chen.
"However, it is such a compelling medium and holds so many associations that artists, designers and filmmakers will continue to use it in their work.
"Neon is increasingly being seen on its own terms. In terms of quantity, neon will recede. In terms of content, it is almost growing."