The British No 1 had battled back from 4-1 down in the decider and had Barty under pressure on her serve when a shot from the Australian appeared to land long, but neither the line judge nor Souza called it out.
Konta confronted Souza, saying: “It’s an absolute joke. You’re making decisions that affect our lives. Do you fully understand that?”
She won only one more point and after a final passing shot from Barty clinched a 6-3 3-6 6-4 victory, Konta walked straight past Souza and off the court.
Several minutes passed before she returned for the trophy ceremony, although she would not say whether she was complaining about what had happened.
It is not the first time the 27-year-old has refused to shake an umpire’s hand, and she said: “At 4-4 in the third set, that’s quite an important time of any match. It’s a difficult position to be in.
“I definitely burned through quite a bit of energy at that moment in time. But, except for one loose shot (in the last game), I don’t think I did too much wrong. Obviously I’m a little bit sad I could not come through with the win today but I’m also taking a lot of positives from this week in general.”
Konta was playing in a final for the first time since doing so here 12 months ago, when she lost to Donna Vekic. It has been a difficult season for a player who was ranked fourth after reaching the semi-finals of Wimbledon last summer and is now down at 22.
She showed impressive resilience here, though, withstanding strong pressure to take the second set and then fighting back in the decider against the top seed and a player regarded as one of the best grass-court exponents.
Konta will hope to build on the positive things in her game in a very tough opening match at the Nature Valley Classic in Birmingham tomorrow against defending champion Petra Kvitova.
Konta’s defeat made it a double British disappointment against Australia after Dan Evans lost 7-6 (7/4) 7-5 to 19-year-old Alex De Minaur in the men’s final earlier.
The 28-year-old had hoped to win the first title of his comeback from a 12-month drugs ban but was nevertheless happy with his week’s work. He now heads to Queen’s Club
“It was a good level,” said Evans. “I had my chances. It’s been a great week leading up to the bigger tournament. He was relentless. That match there has pretty much told me I’m there or thereabouts.”
Despite his excellent form, Evans said he is not expecting to be given a Wimbledon wild card and would be prepared to miss the chance to play at the All England Club if he does well at Queen’s.
Evans, who even suggested he could play two matches in a day to enable him to compete in both competitions, said: “My year doesn’t revolve around just trying to play Wimbledon. But it wouldn’t be my preference to miss the best slam there is.”
Novak Djokovic, meanwhile, is relishing the chance to renew his rivalry with Andy Murray.
Murray is making his long-awaited return at the Fever-Tree Championships at Queen’s Club this week after 11 months out with a hip injury. The Scot had several aborted comebacks, having limped out of Wimbledon last July before going under the knife in January.
The pair, born just a week apart in 1987, have been long-time adversaries on court and have battled at the top of the men’s game for much of the last decade, competing in 19 finals, including seven at grand slams.
Djokovic has also suffered from injury problems over the last 18 months, which saw him undergo elbow surgery.
“I wish him all the best, I really do, tennis misses him, he is a great champion, a great guy, really dedicated, hard working, great ethics,” said Djokovic.
“I really hope to see him back playing at that level he has played over the last couple of years.
“I have known him since we were 11 or 12 years old, I have always had a wonderful relationship with Andy, never experienced anything negative – he deserves the chance to come back.”