No it isn't proof of anything for the reasons you explain above.
Unless you are comparing like with like your "stats" mean **** all.
Not a big fan of the Golden Shoe or Ballon d'or i guess?
Ok how about worst defence in club PL history and with 63 conceded with 4 games to go and only Reading are worse in the league.
Or let's say it's an indicator on just how awful our defence as a team has been
Thats fine. See, you can do it when you try. (and no - not particularly for the reasons you state)
We haven't defended well no - but I don't think this is a reflection on Lambert per se, Vlaar aside, our defence has barely started shaving. I'd hazard a guess at them being by far the youngest and least experienced (in terms of PL games played) in the league. They're kids. They will make mistakes. They have now had a solid season of experience and have got better as the season has gone on.
Moaning about the defence after losing 3-0 to the champions with a couple of dodgy offsides and an absolute wondergoal seems to me to be the wrong time to do it. We are not the club that got hammered by Chelsea. They have come along leaps and bounds, and whilst there is room for improvement they aren't as terrible as you, or the figures suggest.