Really? I've had almost the exact opposite experience.
I've only encountered a handful of situations where someone went out their way to bad mouth someone else to a potential employer. Out of those, only one or two instances swayed the decision maker.
To OP - it's certainly possible that you were indeed bad mouthed. However, the chance of one disgruntled person's opinion affecting someone's hiring decision is pretty slim.
I honestly wouldn't worry about it. Anyone who takes a strangers word about someone else over forming their own opinion is probably not someone you want to work for anyway.
I've only encountered a handful of situations where someone went out their way to bad mouth someone else to a potential employer. Out of those, only one or two instances swayed the decision maker.
To OP - it's certainly possible that you were indeed bad mouthed. However, the chance of one disgruntled person's opinion affecting someone's hiring decision is pretty slim.
I honestly wouldn't worry about it. Anyone who takes a strangers word about someone else over forming their own opinion is probably not someone you want to work for anyway.