To my knowledge from what I have read and researched, jujutsu was the art used on the battlefield, not aikido. I hear aikidoka say this all the time and it drives me nuts. The art used on the battlefield before the 17th century had names like: kogusoku koshi no mawari, torite, yawara and kumiuchi which were supplemental to their main art like kenjutsu or other battlefield weapons during that time.
During the 17th century and beyond, the term jujutsu was used more. Words, terms and history matter. Let's not re-invent it. Nothing against aikido, but it is a modern creation with historical links to DR.
It looks to me like he said aikido techniques
were developed on the battlefield, not aikido.
I think you have to admit that he's got a point there - Aikido's core techniques have been around for quite awhile. Whether you can effectively apply these techniques in a street situation if you practice them within Aikido is a better argument to have.