The article in question is not an interview with the actual Charles Lightoller. The reasons you give are solid:

• The lack of evidence of Lightoller and his wife living in California in 1931, particularly given his documented presence at Dunkirk in 1940.

• The strangely incorrect details about the actions of the Californian that night. The Californian did not receive or respond to the S.O.S. call from the Titanic because the wireless operator, Cyril Evans, had turned off his set for the night.

• The dialect is very stereotypically nautical, and though it could have been embellished by the journalist, it does not fit with what we know of Lightoller through his letters and writings in Titanic and Other Ships.

Other red flags of inaccuracy include:

• Captain Smith was not 81 at the time of the sinking, he was 62. Lightoller had worked with Smith since their time on the Majestic, and would not be 19 years off on his age, particularly given Smith's imminent retirement.

• The interviewee claims the presence of shotguns on the deck during the evacuation. Several survivor accounts noted pistols, including Officer Lightoller, but shotguns were not issued to the crew of the Titanic.

• The interviewee describes the iceberg as "You could see that berg looming up with the naked eye, we was [sic] that close." At the time of the collision, Charles Lightoller was in his cabin, having changed into his pajamas for the night. Officer Murdoch had relieved him on the bridge at 10:00, he had done a duty round of the decks, then retired to his cabin. When he felt the collision, Lightoller stepped out onto the deck, where he met Third Officer Pitman. They could see nothing, and knew they would be called for if needed, so returned to their cabins. Fourth Officer Boxhall later informed both of them of the collision.

• The interviewee states about Collapsible Lifeboat B: "...together we got her righted and climbed in." Collapsible B was not "righted" that night. Those who survived on it, spent the morning seated or standing on the upturned hull as it floated, some with their legs in the icy water until the Carpathia arrived. This is noted in photographic evidence taken during the recovery of victims, as well as published accounts from Lightoller, Jack Thayer, and Harold Bride, all of whom were on it.

For those reasons, it's clear that this interviewee was not Charles Herbert Lightoller, though whoever it was gets credit for the large number of details they did get right, including some details of Lightoller's survival by being buoyed by an air pocket coming out of a vent. They probably read every article and internalized many details. Whether their identity was one of fraud or mental illness is difficult to say.

As to the historical question of the assertion that Officer Murdoch committed suicide by revolver on the deck during the loading of the lifeboats, the record is unfortunately less resolvable. There were many survivor accounts of pistols being drawn, some with shots fired. The following people were alleged to be among those drawing or firing guns:

Captain E.J. Smith

Chief Officer Henry Wilde

First Officer William Murdoch

Second Officer Charles Lightoller

Fifth Officer Harold Lowe

"Master at Arms" (either Thomas King, or Henry Bailey)

Purser Hugh McElroy

1st Class Passenger Major Archibald Butt

And some witnesses simply said "officers" or "crew members", in the singular or plural.

Focusing on Officer Murdoch, who was the most named, one has to note the "telephone game" of witness accounts as they evolved in the press. As seen in this 1931 interview, people's memories (real or manufactured) were often supplemented by details in others' interviews, even actual survivors' accounts would alter over time. Many accounts report a gun being fired into the air, not at people, and in the confusion, some may have heard the documented flare guns and not known the difference. The testimonies given in the U.S. and U.K. investigations do not allege anyone's suicide by pistol, officer or otherwise. Officer Murdoch's body was never recovered by the crew of the Mackay-Bennett, so no forensic evidence is available.

Because of the uncertainty over Officer Murdoch's specific manner of death, filmmakers have often included some version of the incident, because as storytellers they need to increase the tension incrementally toward the climax. Actual events are less tidy than films, of course. Journalists as well, particularly at the time, were given to a bit of inflation in their conflation of accounts -- the more exciting and sensationalist the story, the more papers would sell. On April 15th, 1998, following the opening of James Cameron's film, which portrayed Murdoch as committing suicide, representatives from Twentieth Century Fox presented a cheque for £5,000 to the Stewartry Educational Trust and Dalbeattie High School (Officer Murdoch's school) as a recognition of the distress felt in his hometown over the inclusion of the incident in the film. Neither the studio nor the director has made a statement about the accuracy of the portrayal otherwise.

As a bit of a postscript to the relationship between Officers Lightoller and Murdoch, Officer Lightoller sent the following letter to Officer Murdoch's widow, dated the 24th of April:

"I am writing on behalf of the surviving officers to express our deep sympathy in this, your awful loss. Words cannot convey our feelings, - much less a letter.

"I deeply regret that I missed communicating with you by last mail to refute the reports that were spread in the newspapers. I was practically the last man, and certainly the last officer, to see Mr. Murdoch. He was then endeavouring to launch the starboard forward collapsible boat. I had already got mine from off the top of our quarters. You will understand when I say that I was working the the port side of the ship, and Mr. Murdoch was principally engaged on the starboard side of the ship, filling and launching the boats. Having got my boat down off the top of the house, and there being no time to open it, I left it and ran across to the starboard side, still on top of the quarters. I was then practically looking down on your husband and his men. He was working hard, personally assisting, overhauling the forward boat's fall. At this moment the ship dived, and we were all in the water. Other reports as to the ending are absolutely false. Mr. Murdoch died like a man, doing his duty. Call on us without hesitation for anything we can do for you.

"Yours very sincerely,"

The letter was signed by Officers Lightoller, Boxhall, Pitman and Lowe.
Most historians recognize this letter as a gesture of condolence, not of historical record.

. . . . . . .

References include: Titanic and Other Ships by Charles Herbert Lightoller.

The Sinking of the S.S. Titanic by John B. Thayer III, often included in editions of Titanic: A Survivor's Story by Colonel Archibald Gracie.

A Night to Remember by Walter Lord.

https://www.titanicinquiry.org/ which includes the U.S. Senate inquiry (if a specific lack of testimony can be considered a reference in this case).

http://www.dalbeattie.com/titanic/apol.htm for information about the Twentieth Century Fox cheque.

And various interviews and accounts found in newspapers of the time.