Yes - yes he was.  But nothing like as scientific and single minded as he was afterwards.  A good example of the change in attitude is the way he changed with Frankie Andreu, who  with his wife were good mates to hang out and train with pre cancer, and yet was progressively ostracized post cancer.  Which was a bad move, big time, for Armstrong.  Andreu and Floyd Landis were the main people who took Armstrong down, and latterly George Hincapie too.
But the (doping) riders who gave evidence against Armstrong did so in exchange for having their drugs bans and threat of litigation dropped.  Yet although Armstrong has confessed big time to doping is still under a ban.

I'm no Armstrong apologist - he is seriously not a nice guy, but he is a man who absolutely lives for cycling competition -it defines him, and it seems plain vindictive to treat him so very differently to other dopers.  He even tried to enter a local competition last year (or maybe the year before), and as soon as the organisers found out they cancelled his cycling number.  He was also kicked out of the Livestrong cancer charity he founded, so he is now cut off from that too.

A good example of his not-nice-guy attitude was to go in hard with litigation if anyone published something suggesting he was a doper.  Hubris big time - but no worse than many others.  Like Jeffrey Archer during the prostitute scandal - to a BBC interviewer "If you dare say that again I will sue you personally for every penny you have", or Robert Maxwell shortly before his death/suicide.  Both of them bang to rights, but using their financial clout to try and cover up wrongdoing.  I'm sure their are many other examples.