I don't think "threw a fit" is an accurate description. More like, objected to many aspects for technical reasons. And, considering that TC-39 agreed at the Oslo meeting to pursue ES3.1 over ES4, presumably they had a pretty good argument. Brendan Eich's mail sent after the accord[1] has some detail.

1) https://mail.mozilla.org/pipermail/es-discuss/2008-August/00...

(Disclaimer: I work for MS).