Inconsistent Application of Church Discipline - Why?

[Requiem]

I am perplexed today as a result of discussing with two close friends their vastly different experiences with Church Discipline. I come to CG for some hopefully thoughtful responses.

Allow me to elaborate: Sisters X and Y, both RM's, recently met with their respective Bishops to sincerely confess their sins.

Sister X related a single incident of intercourse with an Elder in her singles ward - also an RM. Her Bishop said that, given the circumstances and her repentant attitude, there was no need to convene a Disciplinary Council and that both parties would simply be placed on an "informal probation", meet regularly with the Bishop, and would have no changes in their status as recommend holders. Sister X came away from the experience feeling great hope and with a resolve not to repeat the behavior.

Sister Y confessed to her Bishop several incidents of "petting". She was subjected to a Bishops Disciplinary Council, placed on formal probation for six months and came away with a broken heart. She was required to surrender her recommend, told she could not pray, speak or even play the organ in a church meeting. She is disconsolate and embarassed to the point where she questions ever returning to full activity. She has not lost her testimony, only her faith in her Bishop.

So, given these vastly different outcomes, why are some Bishops so much more forgiving and tolerant than others? Aren't they being more Christ like in their behaviors? How do I respond to these friends?