Johanna Konta, who relaunches her career under new management and coach in the new year, waved goodbye to an ordinary 2018 on Friday with a late contribution to the Serena Williams debate, declaring she could not side with the all-time great of her sport for the American’s meltdown at the US Open.

Speaking to the Oxford Union about the biggest controversy of the season – when Williams was docked a game that destroyed her momentum in September’s final against the Japanese Naomi Osaka – Konta, the world No 37, said the 23-times grand slam champion was wrong to blame her shock defeat on the umpire, Carlos Ramos. Williams called Ramos “a liar” and “a thief” after receiving three code violations in the second set – one for coaching, which was later admitted by her coach, Patrick Mouratoglou, yet denied by the player.

“I think there [are] a number of different elements that need to be taken into account,” Konta said. “One of them being that the umpire was right: Patrick Mouratoglou was coaching – he said so. [The umpire] gave a coaching violation. I think that has to be taken separately to what happened after.

“One thing that is 100% certain is that emotions are always incredibly high in a match, and I would imagine definitely more so in a grand slam final. Everybody is human, including Serena Williams, and I think the US Open just brings that out of her. I think she feels the stress there, that’s for sure. However, I think you’ve also then got to look at the umpire. That specific umpire is a stickler for the rules. He gave coaching violations to [Novak] Djokovic and to [Rafael] Nadal in different slams.”

Johanna Konta was speaking at the Oxford Union about Serena Williams’s US Open final defeat. Photograph: Maxim Shipenkov/EPA

She added: “I’m all for equal rights but I don’t necessarily always agree [that] when you don’t like something you brush it on to the inequality carpet and say: ‘Because I’m a woman I didn’t get this.’ I don’t necessarily always agree with that approach. However, one thing you cannot take away from Serena is how passionate she is about women’s rights. It is because of people like her and Billie Jean King that conversations are started, topics are put in the forefront and change can be made.

“Now I don’t believe that was a sexist issue, personally. I believe it was emotions running high and things just snowballing. That’s what I believe … don’t hate me, Serena.”

Konta, who reached a career high of No 4 in the world in 2017, tumbled down the rankings this year, parting with her American coach, Michael Joyce, in October to take up with the Frenchman Dimitri Zavialoff. She has also joined the management team of StarWing, who also look after the careers of Kyle Edmund and Stan Wawrinka.