Planner in environmentMode TRACE should detect when the bestSolution is not changed but alters due to a bug in the score calculator implementation

Using incremental score calculation, I've been having weird problems where solutions have outdated scores. These scores are "fixed" when I explicitly call my score calculator on them. After tons of debugging, I was able to produce the attached simplified log file. I will explain it here:

ItineraryAssignment is a planning entity. Lines as these should be clear:
21:28:33.377 [main] DEBUG o.d.p.e.ras2012.ScoreCalculator - Inserting entity: ItineraryAssignment [train=A1, route=0]
21:28:33.377 [main] DEBUG o.d.p.e.ras2012.ScoreCalculator - Inserting entity: ItineraryAssignment [train=A1, route=0]

Lines like this signify that calculateScore() was called on the calculator:
21:28:33.833 [main] DEBUG o.d.p.e.ras2012.ScoreCalculator - Calculating score.

Lines like this mean that setScore() has been called on a Solution. They will finally demonstrate the problem:
21:28:33.867 [main] DEBUG o.d.p.e.ras2012.ProblemSolution - Setting score -968hard/-3409soft to solution RAS2012Solution ...

What we see in the log file is that after a move is done, score is properly re-calculated and set:
21:28:33.922 [main] DEBUG o.d.p.e.r.move.RouteReassignmentMove - Doing move RouteReassignmentMove [train=A2, 0 -> 256].
21:28:34.215 [main] DEBUG o.d.p.e.ras2012.ScoreCalculator - Removing entity: ItineraryAssignment [train=A2, route=0]
21:28:34.216 [main] DEBUG o.d.p.e.r.model.ItineraryAssignment - Creating new itinerary for ItineraryAssignment [train=A2, route=256].
21:28:34.216 [main] DEBUG o.d.p.e.ras2012.ScoreCalculator - Inserting entity: ItineraryAssignment [train=A2, route=256]
21:28:34.223 [main] DEBUG o.d.p.e.ras2012.ScoreCalculator - Calculating score.
21:28:34.232 [main] DEBUG o.d.p.e.ras2012.ProblemSolution - Setting score -300hard/-1294soft to solution RAS2012Solution ...

However, on the undo move for the very same move, no score calculation takes place, no setScore() takes place and no solution is cloned. Resulting in Solution with outdated score:
21:28:34.232 [main] DEBUG o.d.p.e.r.m.RouteReassignmentUndoMove - Doing move RouteReassignmentUndoMove [train=A2, 256 -> 0].
21:28:34.297 [main] DEBUG o.d.p.e.ras2012.ScoreCalculator - Removing entity: ItineraryAssignment [train=A2, route=256]
21:28:34.299 [main] DEBUG o.d.p.e.r.model.ItineraryAssignment - Creating new itinerary for ItineraryAssignment [train=A2, route=0].
21:28:34.299 [main] DEBUG o.d.p.e.ras2012.ScoreCalculator - Inserting entity: ItineraryAssignment [train=A2, route=0]
21:28:34.305 [main] TRACE o.d.p.c.l.decider.DefaultDecider - Move score (-300hard/-1294soft), accepted (true) for move (RouteReassignmentMove [train=A2, 0 -> 256]).

Which is why the move directly after that (which has been hard-coded to throw exception when the score doesn't match the expected one) throws an exception:
21:28:34.305 [main] DEBUG o.d.p.e.r.move.RouteReassignmentMove - Doing move RouteReassignmentMove [train=A2, 0 -> 274].
Exception in thread "main" java.lang.IllegalStateException: RouteReassignmentMove [train=A2, 0 -> 274]: broken score found. Was -300hard/-1294soft but -968hard/-3409soft expected.
at org.drools.planner.examples.ras2012.move.CommonMove.assertValidScore(CommonMove.java:16)
...

Furthermore, setting environmentMode to TRACE actually fixes the issue - this suggests to me that Planner forgets to calculate the score somewhere and TRACE does it instead.