Do the implementations of the Node interface in Web API violate Liskov Substitution Principle?

MDN article on Node interface states that

interfaces [that inherit from Node interface] may return null in particular cases where the methods and properties are not relevant. They may throw an exception - for example when adding children to a node type for which no children can exist.

To me it seems like a strengthening of preconditions in a subtype - a violation of LSP.

Do these implementations actually violate LSP, or is my understanding incorrect?