Wasn't their another oversight, I seem to remember reading a Battle took part in action but was not official recognised and I believe the crew did not get the bar.
You are correct. The 71 squadrons which were credited with taking part in the Battle, and whose aircrews received the Battle of Britain clasp flew the following types:
Hurricane
Spitfire
Blenheim
Beaufighter
Defiant
Gladiator (and Sea Gladiator)
Whirlwind
Grumman Martlet
Fairey Fulmar
No mention of the Fairey Battle.
I once owned a Battle of Britain medal group to a Blenheim Air Gunner of Coastal Command. He was credited with one kill, an Me 109 - no mean feat for a Blenheim I would have thought.