There are a couple of songs that says it takes two, but that’s for love. When it comes to causing grief and heartache for retirement plan sponsor, it only takes one. The one is a plan participant who is adamant of making a complaint about the employer’s retirement plan. For retirement plan sponsors who do nothing to minimize their fiduciary liability, they need to know that it only takes one participant to change everything. This article is about how it only takes one plan participant to cost a plan sponsor dearly in terms of headaches and fiduciary liability.