The scenario described by the transcript isn't a separation breakdown. Visual separation assigned to a pilot is standard ICAO separation. Some questions:
1. the light aircraft wasn't warned about wake turbulence - is that required in the US?
2. Was it an RA or TA? The transcript suggest a TA which in the context would be fine.
An RA would be nasty and require paperwork, but still not a separation breakdown. Poor service and airmanship though to get that close.