It's now been revealed what "that thing" was, and it makes the whole situation even more awkward.
Johnson's 30th birthday party was held on October 5 and was attended by a slew of stars, including Robert Downey Jr., Sean Penn, Miley Cyrus, Johnson's rumoured boyfriend Chris Martin and even Martin's ex-wife Gwyneth Paltrow.
Ellen, as her producer said, couldn't attend because she was out of town. She was actually in Texas where she controversially sat next to former US president George W. Bush at an NFL game.
Knowing that Ellen missed Dakota Johnson’s 30th birthday to hang with her good buddy George Bush really is the icing on the cake.
The NFL game was a PR nightmare for Ellen, who was slammed for sitting next to Bush, with many attacking the talk show host – a prominent gay, liberal and outspoken LGBT activist – for cozying up with the former Republican president, who once endorsed a constitutional amendment against same-sex marriage.
President Bush also entered the US into a war with Iraq and Afghanistan under the later-disproved belief that they possessed weapons of mass destruction.
Actor John Cusack went as far as to accuse DeGeneres of "normalising mass murderers" through association with Mr Bush.
Ellen later addressed the pair's unlikely friendship and the criticism surrounding it on her talk show.
"People were upset. They thought, 'Why is a gay Hollywood liberal sitting next to a conservative Republican present?'" she said.
"I'm friends with George Bush. In fact, I'm friends with a lot of people who don't share the same beliefs that I have. We're all different, and I think that we've forgotten that that's OK that we're all different.
"Just because I don't agree with someone on everything doesn't mean that I'm not going to be friends with them. When I say be kind to one another, I don't only mean the people that think the same way that you do. I mean be kind to everyone."
Ellen's explanation was dismissed by actor Mark Ruffalo, who wrote on Twitter: "Sorry, until George W. Bush is brought to justice for the crimes of the Iraq War, (including American-lead torture, Iraqi deaths & displacement, and the deep scars — emotional & otherwise — inflicted on our military that served his folly), we can't even begin to talk about kindness."
Sorry, until George W. Bush is brought to justice for the crimes of the Iraq War, (including American-lead torture, Iraqi deaths & displacement, and the deep scars—emotional & otherwise—inflicted on our military that served his folly), we can’t even begin to talk about kindness. https://t.co/dpMwfck6su