Comment Re:so what happened? (Score 5, Informative) 55
It's a very good question. It looks like it was mainly failures to generate a result within a predetermined time. Some of the failures were due to cryostat hardware failures (a fridge went out during a NIST campus closure); some due to fiber + interferometer polarization drifts; and so on. It also appears that [perhaps?] a few of the misses are due to latencies in the timetaggers to record a common timebase. I can't quite tell from the arXived version of the paper: https://ancillary-proxy.atarimworker.io?url=https%3A%2F%2Farxiv.org%2Fabs%2F2411.052...
All in all, it's a marvelously good overview of the impressive experiment!