Looking at Oner's interview, Doran's sudden move wasn't unexpected

"The dealer lineup told me to go in"
"I was also planning to go in with Q-flash, but I tried to read the situation and saw the main group couldn't make it. I hesitated for a moment."
"Hyunjun-hyung (Doran) went in."
Basically, when the team gives the order to go in as a Top laner,
you just have to clear your mind and go in.