It's all wrong. 400' AGL is not a regulation, it's a recommendation (been beat to death here). It's not against the law to fly within 5 miles of an airport. I do it all of the time. The correct statement would be that it's illegal without notifying the airport. It's like me stating that it's illegal in all 50 states to drink alcohol.....
and not adding in, unless you are of legal age. Completely changes the statement.
There is also no indication that the person who made the statement even knows that you only need to inform. They got 400' and registration wrong so their track record for knowing what's correct is not stellar.
Again, all 3 statements, as they were made, are incorrect.