always respond, never react

I am currently in a situation where I am employed by a few of my friends who started a business together. One the partners has exhibited severe issues with drug and alcohol abuse over the past years that has led his work, health, and personal relationships to deteriorate. His partners have sat him down many times to try an intervene with the recourse of being terminated from the business.
This has all happened with varying degrees of success. In the last few months, his behavior has greatly improved. He has taken month stints of not drinking at all, he is eating better, he is consistently on time to work and behaving in normal manners.
Last week, one of the partners was struck with information that accused this individual of sexually assaulting two different people a year ago, during the time he was drinking heavily. I have now been asked to join an intervention for this individual to be performed asap. I am feeling uncomfortable with this request:
1. I am being asked by my employers to be a part of an intervention for my coworker and soon to be defunct boss.
2. They are asking to keep the sexual assault allegations out of the intervention, but he is not currently displaying signs of alcohol or drug abuse. It feels forced and I feel I would have to lie to go along with this.
Can you offer any direction? With this brief overview of history, does it sound like an intervention is the correct thing to do? Should I put aside my underlying feelings of discomfort to offer this friend help? It all feels rushed, not clearly thought out and is making me feel uneasy.