I read this scenario well. Gave two possible options and of course one of them was correct. What I could have done in hindsight was to set an order in place (or a OCO order) to capture the move. It was a biggie.
I did take an opposite trade on USDAUD and captured this move. However AUDUSD move was weaker than GBPAUD.
Notice how price breaks out decisively above Fib 61.8% and the upper trend channel. A move worth over 400 pips!