The United Cajun Navy leader who helped find Nolan Wells' body on Horn Island is pushing back on some of Ben Crump's latest claims ... saying key details were presented misleadingly.

Brian Trascher joined us on "TMZ Live" Monday ... accusing Crump's team of using "selective verbiage" during a press conference last week that made parts of the case sound more suspicious than he believes the evidence supports.

Brian pointed to questions surrounding Nolan's phone, including a forensic expert correcting the timeline for the last instance when Nolan locked the device.

He also pushed back on rumors that Nolan's body was dumped where it was found ... saying his own flight over Horn Island that morning tells a different story.

Brian says he flew over the area on July 6 before Nolan was found and saw neither his body nor any boats nearby ... leading him to believe Nolan later drifted into that spot, where he spotted the body hours later.

He also addressed claims about messages being deleted from Nolan's phone ... saying other people in a Snapchat group chat deleted their own messages using their own phones, which then disappeared from Nolan's view too ... rather than getting into Nolan's phone physically.

Still, Brian isn't saying the mystery is solved ... and he believes Nolan's mother has every right to keep asking questions about what happened to her son.

Watch the full interview on "TMZ Live."