Caught president losing head — failed to observe queuing etiquette (3,2)
I believe the answer is:
cut in
'failed to observe queuing etiquette' is the definition.
I can't judge whether this defines the answer.
'caught president losing head' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'president' becomes 'Putin' (Russian president Vladimir Putin).
'losing head' means to remove the first letter.
'putin' with its first letter taken off is 'utin'.
'c'+'utin'='CUT-IN'
Can you help me to learn more?
(Other definitions for cut in that I've seen before include "Interrupt; veer across another vehicle and take its space" , "film clip added later" , "interrupt speaker" , "Start to work" , "Interrupt someone speaking" .)