You are correct, that should not be based off the start time of the pipeline.
I'll create a JIRA and have it addressed, apologies for this.
That's ok. Monitoring tool helped me a lot when creating stats of my business process.
I have fixed this in our CP branch, which will be in the upcoming platform release. The issue is https://jira.jboss.org/jira/browse/JBESB-2078.
I will get it moved across to trunk with the rest of the CP updates.