I think Candace's lawyer's arguments revolved around that the elders did not fulfill their duty of care towards Candace sufficiently. I think this came out when Candace Conti's lawyer questioned the elders regarding what safety measures they had put in place to prevent Kendrick from ever working in the field service with children. Furthermore wt headquarters did not address this asspect of protecting children in their guidelines and instructions to elders either) If this aspect is significantly important then surely it would not matter so much that Candace did not (and was not asked by her lawyer directly enough to) testify to being assigned to work with Kendrick?
I hope that this is the case and that watchtower will be forced to ensure that they fulfill a duty of care towards children in all group activities that are presided over by an elder once this issue has been decided in order that they may not be legally vulnerable (if not for more caring reasons).
Apart from that I think the warning aspect is only relevant in so far as it would have suggested that the elders and watchtower society were at least thinking about their duty of care towards vulnerable children carrying out group activities presided over by elders. This case, imo, made clear that the elders simply forgot about Kendrick. Candace Conti trusted that she was reasonably safe to be assigned to work with anybody.
Okay yes Kendrick did only commit one act of violation but I think Candace's lawyer's questioning did make sufficiently clear that the elders did think Kendrick was an offender and that they did think he was a liar (which they failed to report to headquarters) and therefore, it could be argued, an individual who could not be trusted. Fingers crossed and hoping that the duty of care aspect, which yes would be trailblazing, does bring about a dismissal of wt and body of elders appeals.