Factual error: The portable radio is an AM band only, therefore there is no need for the external telescoping FM antenna.
The Friendly Physician - S2-E29
Factual error: When the castaways are coming back to the island at the end, you can see some of the Los Angeles buildings in the background in the high camera angle.
Topsy-Turvy - S3-E10
Factual error: When looking at the machetes the headhunters had, you can see the molded plastic handles on them. The natives wouldn't have access to such things.
Answer: Hungarian-to-English translation aside, Erika's log-book entries were utterly meaningless. When the radio interviewer expresses confusion, Erika even reads entries from the log: "You take a left at a big, beautiful, pink tropical flower, then pull over and park," and "After the storm, we backed up and made a U-turn," etc. Her directions were scatterbrained, to put it nicely. Additionally, Erika's yacht was forced to leave the island during a tropical storm, and they lost their bearings for several days before the Navy found them. Given that Erika was such a scatterbrain, we might also assume that she didn't hire the most competent yacht crew, either.
Charles Austin Miller