Yes, it is the lactic acid that he is against.

He did resond saying something like, stress creates lactic acid and we don't need any more.

But what he didn't respond to is the fact that during the digestion of milk lactic acid is created so what's the dif.
He may very well be a smart researcher but once he makes a decision about something, that's it. No more thought....I guess!

My feeling is; read all the research and decide what really makes sense.
Leaving something w loose strings always causes confusion.