Originally Posted by seputus

Ahhhhhhhhhhhhhhhhhh............. You are (as you must already know ) absolutely right ..... and so the way to get around this is for me to make the separate one-way booking myself, and then call up to have them take that one-way flight and apply the amex 241 booking over top of it, which results in them not recalculating the taxes.

Only problem is I don't have enough Avios to do that... but at least I understand the rationale now.

Thank you so much.