Laguna wilderness area is mainly mentioned here since it seems to be the most common place that mountain lions are incorrectly reported. With the amount of reports that come out of the Laguna wilderness area, there's bound to be at least a couple reports that contain photos or videos, however, it's never the case. The local park rangers get reports of mountain lions every day, however, there's never photos or evidence like prints, scat, or carcasses. Keep in mind, mountain lions consume a pretty fair amount of prey and would leave behind evidence. For comparison, in the Santa Ana's, whenever there's a mountain lion sighting reported, there's almost always a photo or video that someone got with their phone but the daily reportings west of the 5 freeway in Orange County never have any photos to go with them.
It's understandable that people can mistake some animals for others especially if their life doesn't revolve around the wildlife in the area. Mountain lions are very easy to confirm with photos or videos based on size, stride, looks, and behavior. If you have to question whether or not your sighting is a mountain lion, it's almost for sure not a mountain lion. In some humans brains, we want things to be bigger and scarier, people will convince themselves that what they're seeing is a mountain lion, even to the point that they won't listen to reason from experts. This is typically where the problems begin, when people have the mindset that everyone else is wrong and they don't even want to hear anyone disagreeing with them. You might see them respond only to people acknowledging those who agree with them but ignore the people with valid points. If you have someone with this mindset, they cannot be relied on as a credible source.
Some people want to have a cool story about the time they saw a mountain lion, "it was so scary!" It's something we do as humans, it's understandable. Often, people will even claim that it was a baby mountain, sometimes even saying its tail was cutoff. This is just not something that happens, it would be extremely rare for a mountain lions tail to be cut off somehow, yet most of the unconfirmed reports say this. As for a baby or juvenile mountain lion, mountain lions cubs stay with their mothers for about 2 years. With most of the reports claiming to be juveniles, this also proves the point. Mountain lion cubs are already pretty much full size at 1 year old and still traveling with their mother for another year. Mountain lion cubs smaller than that would likely not be able to survive on their own. It seems strange that almost all the reports in Laguna wilderness claim to be juveniles and no adult is ever seen. Now, it could be possible that a baby mountain lion got separated from its mother somehow but it would be pretty rare and weird for a mother to just abandon her kitten.
As for the areas with the most commonly reported cases of mistaken identity: Laguna Beach, Aliso Viejo, and Carbon Canyon. None of these areas have had a confirmed mountain lion sighting within the last 40 years or so years since Orange County became very developed, except for in early 2022 when a young male mountain lion did happen to make its way into Laguna. This became a big deal and there were several photos and videos of him being spotted randomly around Laguna Beach and Newport Coast before he was captured and relocated. There was lots of proof of him being around.
These areas are also some of the most heavily used wilderness areas by humans which means the odds of someone getting a mountain lion on camera are much greater than areas like the Santa Ana Mountains, but nobody ever does. If you live on the coastal side of the 5 freeway, you can rest assured that you probably won't encounter a mountain lion. Now, of course a mountain lion can go wherever it pleases, it can certainly roam through city and get to here or there but it would be extremely rare. It's already rare enough to even see one in the Santa Ana's where they are known to inhabit. Of course, anytime you venture into any wilderness, you should always be aware of your surroundings and know how to act accordingly with wildlife. Some outdoor spaces and parks have mountain lion warning signs but they have to for liability in case one ever does show up.