Crazy family - might be responsible for slip (6,4)
I believe the answer is:
banana skin
'be responsible for slip' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'crazy family' is the wordplay.
'crazy' becomes 'bananas' (I can't justify this - if you can you should give a lot more credence to this answer).
'family' becomes 'kin' (synonyms).
'bananas'+'kin'='BANANA SKIN'
'might' is the link.
Can you help me to learn more?
(Other definitions for banana skin that I've seen before include "potential hazard" , "something to cause embarrassment" , "A disaster waiting to happen" , "Potential disaster" , "that could lead to one's downfall" .)