It appears you may be right. However, I believe the text move was played for instructive purposes. We really should not apply computer analysis to many of the Chess Mentor lessons as sometimes a second best move may be played for instructive purposes as is the case here.
Error in PEB081: Weaknesses?
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of course you are right and i didn't want you to change the lesson. I don't use a computer to be a jerk about Chess Mentor, just to grasp every aspect of the lessons.
And i totally agree that second best moves should be played for instructive reasons. Just wanted to point the draw out.
Thanks for your answer
Jul 19, 2009
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#4
I just tried this lesson out of curiosity : it's really very interesting !
However, I have the feeling that some alternative moves have been missed for white, but haven't checked with any computer so I may be wrong here. If I find anything convincing I will post it later. Thank you for your contribution sirprim. 
It appears that Black has an opportunity to draw after 7. ... f5+ instead of 7. ... a6. Glaurung 2.2 suggests for black to never move your pawns again. So your pawns on a7, c6 and e5 nicely control the infiltration squares on the queenside while white can make no progress on the kingside because Black has the Opposition at that moment.
But a really nice lesson nevertheless.