Further to the grounding of the Caribou fleet, the main driver for that was the one that had a structural failure due fatigue at Efogi in PNG in 2008.
Many would have seen the photos
(here, in post 15:
http://www.pprune.org/military-aircr...e-caribou.html of the port engine hanging a foot or so lower than the starboard. I believe they landed for a crew changeover, which was thankfully when the damage was noticed.
If they'd just turned around and taken off again without anyone getting out for a look, it would have been very nasty.