Well done Kiwikid, a lovely clue. However, do I need to upgrade my reference books because I can't find 'rt' to mean 'real time' anywhere or is it a musical term which I'm not too hot on.
If I may, this is how I parse it and please tell me if I'm missing something.
Homo sapiens’ stratagem taken to new levels when credit replaces real time offering (5,9)
Homo sapiens' = Human s
stratagem = artifice
when credit = CR replaces real time RT
'a (rt) ifice' - becomes - 'a (cr) ifice'
Human s a (cr) ifice
offering = Def