Need to give boss a list of my mistakes?

I have been a top performer for 3 years at my organization. I have often been tasked with taking on a very large workload on my own and have trained a few of my colleagues. I have made some process improvements for the organization as well.

A few mistakes have been made on my recent project, and now my boss is asking for a list of everything that went wrong and has scheduled hours for us to do this. Percentage wise, the errors are low though can be high impact.

Should I be concerned this is for a PIP?