Actually, it goes further than that. Everyone but IE seems to just return the value of the content attribute when you do a get on the IDL attribute:
<!doctype html>
<script>
var el = document.createElement("form");
el.setAttribute("method", "invalid value");
alert(el.method);
</script>
IE alerts "get", everyone else alerts "invalid value". Are non-IE
implementers interested in changing to match IE here? IE's behavior
seems more useful.
