A new data point appeared on a Facebook group today:
https://imgur.com/a/lKnAC4W
Looks like SQ and United Airlines are best friends here!
1 itinerary/trip/reservation = 1 flight
In case you were wondering, the itinerary in question was:
HND>SIN
SIN>MLE
MLE>SIN
SIN>HND
booked on a single PNR
Is this a flight YOU took? Is the SA customer service text to you or some person on FB? Would be nice to have a link to the FB group.