Moiraine wasn't severed, and neither was Lanfear when they feel through the doorframe ter'angreal.

Many people thought they were.

Now, knowing this, how did the two of the allow themselves to be captured? The Aelfinn and Eelfinn are NOT immune to the OP, and certainly not immune to objects being thrown at or onn them. So how did LANFEAR allow a bunch of fur coats and leather shoes take her?

She should have ripped the crap out of them, same for Moiraine.

Only possibility is they got knocked out when they fell in and woke up captured, but STILL the Ael/Eel can't shield them as far a we know, and they dont know forkroot as far as we know, plus we DO know that they were granted wishes so they were AWAKE at some point, ALSO they fell thru the doorway so there were 'rules of engagement' for the Ael/Eel.