I may not be able to answer this in Western Traditional Med terms, but I'll try to translate.
A little background first: Massage in the States combines a lot of Chinese Medicinal (as well as some Ayruvedic) philosophies and theories on how the body functions with Traditional Medicinal/Scientific study.
The concept he was talking about was a very short version of how the blocking of Qi (chi = the universal energy that surrounds, flows through, and sustains life) can manifest itself.
Our bodies have ways of holding stress, through our various systems, that can manifest itself more subtly than just feeling pain or feeling ill. From centuries of study (though not as scientifically proven as we'd like it, so we down play these concepts though they came well before Gregor Mendel brought us genetics and before our modern scientific method was born) the Chinese have noticed that certain stimuli produce a number of results. Many of us Massage Therapist have to study these claims, and the methods by which the data was compiled, and use them to our clients' benefit. Unfortunately, not all use the scientific method to explain what's going on and not always is it possible to speak to the modern rational thinker in terms that he can understand.
So, not having worked on you, I couldn't say that what he told you is a load of horseshit, but I know he couldn't prove his findings to you either outside of the fact that you felt better after he worked on you. Energy work can release endorphines and other good feeling hormones through the Therapist's manipulation of your bodies systems using lots of hypothesis and unproven theory. However, he didn't hurt you or claim to heal a disease of yours, so next time just nod and smile.
I hope somehow, something in what I've written made sense.