This has happened on rides I lead. If you have signed the waiver and have the cue sheet AND tell me that you are "officially leaving the ride" then it is OK. AMC has a very specific liability policy for this. On our second ride this year (in March) which was billed as an intermediate level spring warm up ride, with hills, 2 people came that are also leaders. Within 2 miles it was clear that they could not keep up. Our average was about 14, but these women usually lead slower paced rides. Since I was sweeping, they told me to go ahead and I did. When i emailed one of them later, she said it took them 4 hours to do the ride that took us 2! But, there was another woman there who clearly had overestimated her qualifications for the ride (all participants are screened for these rides and this one must have felt OK lying to me) and since she was from the city, she did not want to do the ride alone, as she was really unfamiliar with the area, even though there was a cue sheet. The result was the group stopped and waited for me and her at the intersections, but eventually, near the end, I told them to go ahead. It was a really miserable ride for me, but it was my job, and I stayed with her. However, on the climbs, I did go ahead and wait for her at the top.