The movie only shows that Helen says she will do anything to save her husband's life. Lawson then kisses Helen roughly. The scene then switches back to the beach where Doug is trapped and the tide is rising. Whether or not Lawson ended up having sex with Helen is in the eye of the viewer.
Where is the Baja Peninsula?
The Baja Peninsula is a long thin finger of land, mostly belonging to Mexico, that projects southward from southern California. It is bordered on the east by the Gulf of California, which separates it from mainland Mexico, and on the west by the Pacific Ocean. A map of the Baja Peninsula can be seen here. On it, you can follow the Stilwins' route on highway 1 from Tijuana to Ensanada and all the way down to La Paz, as described by Helen Stilwin.
What is 'Jeopardy' about?
The Stilwin family -- father Doug (Barry Sullivan, mother Helen (Barbara Stanwyck), and son Bobby (Lee Aaker) -- are vacationing on an isolated beach along the coast of the Baja Peninsula. When Bobby gets his leg trapped on a deserted jetty, Dad goes to help but the pier collapses, trapping Doug's foot under a heavy piling log. With the tide coming in, Helen tries to find help. She enlists the aid of another American, Lawson (Ralph Meeker) but soon learns that he's an escaped criminal, wanted for murder, and his efforts to escape compromise Helen's efforts to save her husband.