Kraken is still silly for going after them, IMO, but the Kraken case isn't as cut and dry. The person who had left the review on Kraken had accepted a large severance package that was conditional on signing a NDA.
I think the bad PR Kraken got for going after them wasn't worth it (especially as the review wasn't really even that bad) but the ex-employee was also not really in the right there either, having violated their NDA.