As if it wasn't synchronous enough for Chinese-American playwright David Henry Hwang's sparkling comedy Yellow Face to transfer to the National Theatre Shed in the week that Vietnam war musical Miss Saigon opened in London, it landed right in the middle of yet another row over racism in BBC television show Top Gear.

Hwang's 2007 satire was a response to the Miss Saigon controversy, which began in 1991, when white actor Jonathan Pryce reprised his London role as the Eurasian Engineer on Broadway, prompting American anti-racists to kick up, ending the practice of using non Asians in Asian roles. Or so we hoped.

Two decades later, when Britain's Royal Shakespeare Company cast East Asian actors in just three minor roles (out of 17) for its "Chinese Hamlet", The Orphan of Zhao, social networks exploded with protests from around the world - and from Hwang.

Almost the entire British theatre establishment rose up to crush the upstarts. Arts reviewer Mark Shenton attacked me and Hwang by name, so there was no way I was going to miss Yellow Face's pre-show debate between playwright and critic.

You have to admire Shenton for daring to turn up and address an audience of Asian Hwang fans. Less confrontational in person than in print, Shenton reiterated that an ensemble cast for the RSC's three-play season couldn't possibly have had Asian actors play leads in them all, even though one was Boris Godunov (set in Russia) and the other was Life of Galileo, by that well-known realist Bertolt Brecht.

"So, Mark," I asked, "did you see yourself in [ Yellow Face]?"

Shenton blustered that there wasn't a big enough pool of East Asian talent … to a room of assorted East Asian talent, a year after we broke through in the West End with Asia-themed plays.

Hwang asked why people should cherry-pick what they think is cool about Asian culture, and said he preferred that they didn't do his plays if they were going to exclude Asians, who should have had at least some leading roles in Zhao.

That night, Hwang finally saw Miss Saigon.

"The show totally empowers white men," he said. "Poor Chris, torn between the white wife and Vietnamese hooker who both adore him. Kim would rather have run away to become a prostitute than marry the handsome Asian rebel who searched THREE YEARS for her!

"That said, the production was quite well done, with a spectacular performance by the Engineer … I came away with disturbingly conflicted feelings."