Property definitions that attempt to override JS Global Object are silently ignored

Relevant doc: "QML disallows element, id and property names that conflict with the properties on the global object to prevent any confusion."
If you try to use a Global Object property name as id, you get an error, as expected. However, when a property definition attempts to override such a property, the definition is silently ignored.
Example:

import Qt 4.7
Item {
    property string parseInt: "hello"
    Component.onCompleted: console.log(parseInt);
}

Output:

function parseInt() {
[native code]
}