Electric shock from standard outlet?

A guy I work with was checking a power cord today and when he went to push the plug all the way back in it 'popped'. He said that because his other hand that he wasn't using wasn't crossed over his chest, that he prevented himself from potentially having a heart attack... His other hand was away from his body. Is this true? Doesn't/wouldn't the current just ground itself through him regardless of where his hands were? The outlet was a standard 120V 60Hz outlet. If he is correct, why would the placement of your hands make a difference?