I tried setting up an ElevationDetector followed by a custom detector, and expected my custom detector to only be called once elevation was above 0. I was expecting orekit to not evaluate detector B if A is false when adding [A, B] using andCombine(). However, this does not seem to be the case. So am I right in assuming that orekit does not use short-circuit evaluation of Detectors?
You are right.
This is a known issue (and has been for a while), see issue 475.
We should really address this.