I understand what you mean. But for most post people from all around the world,any country below mexico is a part of south america. Therefore they think that costa rica is in south america. Just like many people still mistake central european countries for eastern european countries. Or vice versa. Many people says that hungary,croatia,slovakia,republic czech,ect... are central european countries. But others says that these countries belongs to east europe. Same thing with israel. Some says that israel is in north africa and others says that its in asia. I think you get the point.
Latin america is vast and diverse. Therefore mistaken honduras or ecuador for being in south america is common. These countries are very close to south america. Especially when you look at the map of south america. So you know that most people will include latin america in south america. Not everything as to be 100% pristine accurate. So its not a big mistake to say that costa rica is in south america. Brazil is in south america. They even said it at the 2016 olympics in brazil. Some dont consider poppers a drug. Even though it is a drug. But its a softer drug. Therefore it cant be seen as risky. So it cant be a a part of real drugs. Its all about perception.
For example, if there was a summer song called Fiesta Caliente (The South American Anthem) some of the lyrics from this dance song would be ''put your hands up in the air for CHILE,BOLIVIA,PANAMA,VENEZUELA,BRAZIL,PERU,HONDURAS,GUATEMALA,ARGENTINA,ect...'' Then this song, even though have some latin america countries in it,still could be called The South American Anthem. So,referring to these countries as south american is not totally off. And really no big deal.