I strongly doubt because there have been several times when I've forgotten kefir containers to a cupboard for a longer period of time (up to two weeks), and they've always been full of molds, in every colour of the rainbow - purple, green, orange, red, blue.
I try to clean the cupboard when I remember, with strong etheric oils, but that haven't helped.
The milk should be fine. It's from (truly) organic farm.
However, at least there's no rapid reaction like nausea or something like that.