Is one of the multiple "incoherences" from a narrative point of view, just like the fact that if the player has discovered the deep betrayal of Kagha there's no dialogue option to inform Halsin neitherr before nor after the quest end , litterally the only way to manage the dark druid's infiltration is an open fight.
I really hope these plotholes will be solved because just like you said it's weird that not only a druid, who usually are prone to not interfere with the ways of nature (that is if the Thieflings are not able to defende themselves, well tha's parto of the natural cycle), but a good or altruistic character won't share the information about the difficulties that fill both the two roads to Baldur's Gate.
