Screw Cap wines – are they truly free from being faulted?

Screw caps are being touted as the savior of modern wine, supposedly reducing the instances of faulted wine.  I have recently opened some screw cap wines that have been off due to not being sealed properly, therefore allowing air into the wine and oxidizing it. The wine in this particular box was lying on its side and the bottle was slowly leaking wine out at the top of the cap as well.  I’m not sure if shipment and lying of the wine down as oppose to it being up right had anything to do with it.   My guess is that it had to do with the capping machine just not capping it properly (even machines are not perfect).
 
We all know that screw cap wines do not need contact with cap like wines with bottled with a cork, so why did this particular producer lay down screw cap wines in the box?  Is it to save packaging or make the box smaller?  Either way, I think wines that are screw capped should be stored and shipped in the box upright and quality checks should be done on caps to prevent wines from becoming oxidized.
 
We’ve all opened a bottle of pop that somehow lost its carbonation long before it we drank it, so I think we will still have to keep our noses on screw cap wines.