Is Aikido A Martial Art?

You obviously are , your "attack" was unprovoked and inappropriate , when I , and indeed anyone I respect , has taught it's always been made clear that you only hit someone if there's absolutely no other option , and this is absolutely hammered home to kids.
To share a story of my own , In karate we do short drills called ippons that are very similar to the kind of thing you were demonstrating.
I was on a course with sensei Kawasoe going through ippon kumite , at the time we were doing a dead simple one , tori steps forward with jodan tsuki , uke defends with age uke chudan gyakuzuki , ukes punch should always be pulled at the point of contact , much as your tenchi nagi should have gone over his shoulder rather than through his face.
We were doing this in a "bicycle chain" and I clocked my next partner was sinking in his counter punch and hurting his partners , so on the next change we bowed and he proceeded to to use me as a punch bag , when it was my turn to counter punch I decked him with my first shot , when he got up I said "understand ?" he nodded and we carried on in a more "traditional" manner , though I'm not overly proud of hitting him like that , I was pleased to see he was much more polite for the rest of the drill.
I think you were very lucky that the kote gaeshi he demonstrated next was so polite.

 

All of the above.

I'm honestly stunned.

When we train we put our trust in other people. Icefield makes the point and the distinction perfectly.

Deliberately injuring someone who has given you that trust is the egotistical action of a spoiled child. Dean makes that point very well too.

Personally, I will never train with or teach a session involving someone who views the safety of others with such disregard, whether that be in my own club, at seminars or MAPMeets.

Mitch

Edit to add: In some ways it is an abuse of my Mod powers to post on a locked thread like this, for which I apologise. However, I was away and without access to MAP when this was posted and wanted to make clear that
1. There is no MAP Mod consensus on this, we are individuals with different views.
2. As an Instructor I would not want any of my students to feel threatened in a compliant situation when they have placed their trust in another. I will not be seen to condone that.