[maxmouchet]

I can't speak for AWS specifically, but in my PhD thesis [1] I found a bunch of such examples by using RIPE Atlas probes. Essentially looking for pairs of probes where the RTT between probe A and probe C is larger than probe A-B + B-C.

Now there are some issues with this methodology (all common issues with ICMP/RTT measurements + traffic was not really routed through the "relay" probe), but such pairs do exist.

[1] https://theses.hal.science/tel-03666771/document (see page 84 for an example; if you can read French :-))