So the first issue is adverse possession. There are 5 elements which must be met to adversely possess property and become the true owner.
You must have actual possession of the property. You can only adversely possess (AP) the property you use. So if I'm AP a cabin on 100 acres but I only use the cabin and 20 acres I will only be able to legally claim the 20 acres and the cabin. (there is an exception which allows you to take all those acres called color of title but it is reserved for a sale with a void deed so n/a in this situtation)
That possession must be hostile to the true owner and other trespassers. You have entered the land without consent of the true owner. Courts have 3 views of this based on jurisdiction but the common law rule is that it was without permission.
It must be open and notorious which means visible and apparent enough so that a reasonable owner would be put on notice that someone is there. It appears as if the adverse possessor is the true owner. The true owner doesn't need to actually know just that you used it openly enough that they should have known. An example would be changing the locks and painting the house, mowing the lawn. It cannot be a clandestine activity.
Continuous possession of the property as any other reasonable owner would. This doesn't mean you live there 24/7 just that you use it continuously as any owner would. So a seasonal cabin would only need to be used in season. And as long as you leave with the intent to return or if you leave someone in charge of looking after it for you it is continuous.
The possession must also be exclusive both from the true owner and other trespassers. You must in a sense exclude the owner. If they never show up that doesn't matter because you've still excluded them. If they come by and use the land as if they are the true owner it will be hard to argue the "they've been excluded angle" but if they ask for permission (to say pick apples from the land you are AP) then they've still be excluded. Because you've denied them their rights of acting as the true owner.
Finally the last pseudo element is that all 5 must be met for the statutory period (usually 10 years but it varies from state to state). The period starts the day the AP'er starts trespassing.
If you have met all of these elements for the statutory period then you can go to court and ask for a quite title or if the true owner tries to kick you out as a trespasser you can raise AP as an affirmative defense.
So here is what he got wrong/mixed up with regards to AP.
The guy gets the idea of adverse possession sort of right with possession is 9/10th of the law. But in reality in property law there is always the legal presumption (default position the court will assume) that the one in possession (they have physical dominion and control over the property) is the owner unless you can prove a better claim than them. The idea behind AP is that if you don't use the property and you effectively allow someone to adversely possess the property they have been a better owner. Its a way for people to claim "abandoned" property and use it better than the actual owner is.
Here is where he mixes up Landlord Tenant law with trespassing. If you own property and see and AP'er on your property you are allowed to kick them out and call the cops (called self-help). As long as you are the true owner and the statutory period is not met doesn't matter if you call the cops to remove them 2 say after they started to AP or 9 years after AP.
It is true that a Landlord cannot just kick out a tenant a landlord must go through a summary process (bench trial). To become a tenant however is more complicated then just not knowing someone is using your property. There still must be a lease agreement. The agreement can be oral or contractual. If the trespasser was to pay the Landlord each month $50 that would become an oral agreement. For this women to say she was a tenant would need to prove up some kind of lease agreement.
Here is the biggest problem with his whole argument. You cannot be both an adverse possessor AND a tenant. A tenant has permission to be there by the true owner. An adverse possessor is a trespasser and is doing so without consent. If at any point (before the statutory period) the true owner gives the AP'er permission to be there they lose exclusive and hostile elements of adverse possession.
There are more details I could get into but since I just took an exam on this I really don't want to dive in too deep but let me just say that he knows the layman's view of issues that are as deep as the sea.