But the real problem here goes all the way back to when CBS first developed the show. And it's not the only drama on the network with this difficulty.
When CBS first created the new Hawaii Five-0, it retained the old show's formula of centering the action on two white male stars, setting up talented actors like Kim and Park to play second fiddle for the life of the series.
"I don't understand why we're dealing with this issue now," says Brenda Ching, executive director of the Hawaii chapter of the performers' union SAG-AFTRA. "Obviously, the success of the show has been phenomenal, and everybody's role has built the show. ... Even if you look back to the original Five-0, what made the show was the diversity of the environment."
CBS has long followed the formula of surrounding white male leads with a diverse group of supporting characters (NCIS: New Orleans, Bull, the MacGyver remake). They have tweaked that pattern occasionally to actually feature women and people of color as co-leads (NCIS: Los Angeles, Elementary, Superior Donuts).
But when CBS debuts its fall season in September, the network will have just one show that features a nonwhite person as the sole lead character: a reboot of S.W.A.T., starring Shemar Moore, who is biracial.
This is why diversity is so important for networks to embrace: Decisions made at the beginning of a show's life have ripple effects that extend throughout the life of the show and across the network for years to come.
Complicating things further is the way Hawaii Five-0 marketing material often framed O'Loughlin, Caan, Park and Kim as equal characters, in some cases putting Park and Kim front and center. For anyone looking to criticize the show for focusing on white characters, the pictures could argue otherwise — but it also could lead fans to assume all four characters were an equal ensemble in every way, including pay.
As the controversy over Kim's and Park's departures grew, Hawaii Five-0 executive producer Peter Lenkov posted a note on Twitter saying the actors "chose not to extend their contracts" after "getting unprecedented raises" in negotiations, listing the diversity of actors elsewhere in the cast. CBS issued a statement praising Kim and Park, noting they "tried very hard to keep them with offers for large and significant salary increases." Variety has reported that Caan and O'Loughlin make about $200,000 per episode, plus a small share of the show's back-end profits; Kim was offered a salary about $5,000 short of the show's leads and a production deal.
Kim issued a statement on Facebook thanking fans, the network and those who worked on the show. He noted, "As an Asian American actor, I know first-hand how difficult it is to find opportunities at all," later adding, "The path to equality is rarely easy."
Oka emailed a statement to NPR:
"I was as saddened as anyone to learn of Daniel and Grace leaving Hawaii Five-0 but I, probably more so than most, understand their reason for doing so. Sometimes you have to draw the line in the sand for something you believe in and something for which you stand. While pay equality was not my personal primary decision to leave ... I support [Kim] and [Park] in their decision to stand up for what they believe is right."
It's true that it isn't unusual for long-running TV shows to lose cast members as the program ages — everyone seeks pay raises, and the network tries to keep a handle on costs. Kim and Park were also different negotiations, and Lenkov said Park declined an opportunity to appear in a handful of episodes next season.
But these are specific issues connected to a larger, structural problem.
For years, I've used Hawaii Five-0 star O'Loughlin's career as an example of how the TV industry gives white males the kinds of opportunities actors of color rarely share.
O'Loughlin 's first starring role on CBS was as a vampire private eye in the drama series Moonlight, which was canceled after its first season in 2008. A year later, the Australian actor was playing a Pittsburgh-based transplant surgeon on the CBS medical drama Three Rivers, which was also canceled after its first season. CBS clearly wanted to be in the O'Loughlin business, and it finally found success casting him in a program that seemed poised to do well — a 2010 remake of a beloved CBS cop show.
But given that Kim had co-starred on the hit show Lost and Park had co-starred on the critically acclaimed reboot of Battlestar Galactica, it's tough to understand why it was so hard for CBS and the show's producers to pay them as O'Loughlin's equals.
The network has a similar problem with gender. For the second year in a row, every new CBS show this fall will star men, and all but one will star white men. Last TV season, CBS had one new scripted show starring a woman (Doubt, featuring Katherine Heigl), but it was quickly canceled (the network is burning off unaired episodes this summer). CBS hasn't announced any new scripted shows starring women for the 2017-2018 season.
So what happens the next time the network faces a pay dispute with a female co-star on a TV show?
Shows like Doubt, S.W.A.T. and Superior Donuts (where co-star Jermaine Fowler, who is black, is also an executive producer) seem like efforts by CBS to break the pattern. But that change is coming too gradually; today, the worlds CBS portrays are out of step with the diversity of real life.