It is hard to quantify success or failure at 10min or 12min. I tend to look at the exact questions the rep is asking before moving into another phase of the call. Without hearing the call or seeing the questions -- it would appear (on the surface) that the questions aren't uncovering the true pain points for the customer. When that happens, nothing else they say will matter as they've missed the mark. So, proper discovery will ensure they've uncovered their true pain, verified it, and only then should they move into another phase of the call.
