Never claimed that UAE is conservative with prison sentences.
But having lived there for decade I can tell, in this particular case we are discussing UAE courts would not be quick to give life sentence.
UAE is in the hot region and their CID is doing an amazing job keeping UAE safe. As I recall this guy's case was somehow related to other much more serious cases where a bunch of UAE nationals got their life sentences as well. I, personally, have little sympathy to those who sabotage and disrupt peace in the region and I have no reasons to suspect CID to play stupid games in this particular case.