Is this dress too short ? Lady gets bullied for rocking this dress to a wedding

Is this dress too short for a wedding?  A friend of the unnamed guest posted a picture to a New Zealand radio station' The Breeze's Facebook page on Sunday with a simple question.

 Can we get some advice from you please? A friend wore this dress to a wedding in the weekend and got targeted big time. She says she got treated rudely by other women at the wedding who saw her as a target for wearing this dress.
A woman came up behind her and slapped her on the bum and said it was on a dare from a group of other women who were watching and snickering. Someone else seemingly purposely spilt a beer on her.
She's amazed that grown women could be so immature and such bullies. Okay, but wait. She wants to know - Did she bring ANY of this on herself by wearing this dress to a wedding? Your thoughts?