Not caring which container, whatever happens (2,3,4)
I believe the answer is:
in any case
'whatever happens' is the definition.
(I've seen this before)
'not caring which container' is the wordplay.
I cannot quite see how this works, but
'container' could be 'case' (case is a kind of container) and 'case' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for in any case that I've seen before include "Lawyers may be so employed" , "No matter what" , "Besides" , "At all events" , "Where customs officers may search" .)