There are enough moving parts and conflicting incentives within the system that it's unlikely to be that simple. In theory, yes, they may have underpriced their IPO and left some money on the table, but that isn't necessarily the worst thing. In general, it's better to be thought of as a company that's outperformed expectations than underperformed them.

Perhaps, but keep in mind they sold only a small portion (~12%) of the company in the IPO, so the effect on the overall value (and longterm success) was limited.