During the first month ashore in Normandy, it was noted he was "jumpy and high strung". The quartermaster of the 3rd Division, Côté was frustrated with Keller's chronic indecisiveness on D-Day and later stated in an interview that the responsibility of command seemed to be too much for him. Keller's immediate superiors in I British Corps and 2nd British Army considered him unfit to command the division, but Lieutenant General Guy Simonds, who was scheduled to command II Canadian Corps upon its activation in Normandy, held off on making a decision about his relief, even refusing a resignation by Keller who himself admitted to the strain. During the Battle for Caen, Keller handled Operation Windsor poorly, sending a reinforced brigade in to handle a divisional operation and delegating the planning to one of his brigadiers. Keller was also reportedly shell-shy by August, and rumours began to spread among the division that "Keller was yeller."