SDWAN traffic - where does it go, can I show?

[ChrisCon]

A few days ago on one of our Palo Alto firewalls the primary (MPLS) line was down (not the provider router, somewhere between there was a broken cable) and traffic was routed over backup (Internet). 
Because provider router was up, the interface on Palo Alto was up, so this was no indication for traffic routing over backup.
I only could see this in the monitoring PRTG, but is there an easy way to find it on Panorama or the Palo Alto firewall itself?
GUI or CLI?
Thank you.

[BPry]

@ChrisCon,

Have you looked into the show sdwan options present in the API and CLI? show sdwan event I imagine will display sdwan path-monitoring events.