Both were instrumental to a successful landing. Aldrin was busy dealing with things like cockpit alarms and repeated reboots of the main navigation and control computer. (Said computer was busy doing things like keeping the LM upright and not spinning.) The landing would not have been successful without last minute decision making by both crew members.
The sad news broke tonight : Neil Armstrong, the first human to ever walk another world, died today. We lost him forever. He died before we could defeat death.
Once again the horror of death strikes. This time, in addition from wiping from us forever a hero of humanity, he wiped from us forever a memory that will never exist again. Never again will a human being be able to experience being the first to walk another world. That beautiful experience is lost forever too, along with all the memories, dreams, desires and wishes that made Neil Armstrong.
But thanks to him, humanity made a giant leap. We'll fill the stars and conquer death. The spark of intelligence and sentience will not extinguish. That's the best we can do to honour him.
Source : http://www.reuters.com/article/2012/08/25/us-usa-neilarmstrong-idUSBRE87O0B020120825