Caz
Just about every time you get airborne, at some stage or other you proceed towards a mass of cloud.
The trick is not to enter it at below Safety Altitude.
If the crew could clearly see this this cloudmass from 2nms then approaching it and turning just short (say 0.5nm), should not present a problem.
That they did not do this suggests:
1. Technical Malfunction (FADEC UFCM).
2. Misjudgment of range. Which is Aircrew Error.
What you describe does not show negligence. And do remember, Wratten and Day assert that negligence had already taken place before Waypoint Change. You seem to be contending that it happened after.