If a person you've praised causes some kind of serious damage at the next place they work, that employer could come after you for having 'misled' them by recommending him or her. Even a glowing reference could get you hauled into court, not just negative ones.
On September 11, a Marilyn Monroe impersonator sang a sultry rendition of "Happy Birthday" to an executive at the Virginia headquarters of the Society for Human Resource Management. The brief performance, which took place in a conference room with about 75 employees, came after remarks honoring the 24th anniversary of the 2001 terror attacks. Two former staffers who were present at the gathering, recordings of which were reviewed by Business Insider, said it was uncomfortable to see - and not just because it was sexually suggestive.