Avoid assigning blame and present the situation objectively with empathy. Take responsibility for your part and offer what you learned from the experience. Avoid examples of physically or verbally abusive behaviour which resulted in corrective action.

My supervisor asked me to help a peer who seemed like they took on more projects than they could handle. I offered advice, but their response was defensive. I had no intention of taking credit for their hard work, so I monitored their performance from a distance. I noticed a potential error which might have negatively impacted the business, I stepped in and kept it on the down low. They were appreciative. Changing their perspective of me, from competition to ally, they relied on my experience moving forward, and we're close friends to this day.