deleting the item from ml_labeled_data resolved the issue.

From HIWAVE Ticket: It looks like the long text was not picked up as an "utterance" but rather as a snippet of text from the VA Chat Logs. This would explain why you cannot find it under the sys_nlu_utterance table (and likewise why the validate length business rule did not block the record in the first place). I was able to find the text under the [ml_labeled_data] table. I will admit our documentation does not make it clear that the "utterances" you see in Expert Feedback Loop are not actual Utterances but rather just snippets of text.