DMTN-020 section 9.2.2. gives good guidelines on how an pic should be written including "a clearly defined deliverable".
It is the responsibility of each TCAM to check these deliverables are available (link to code repo/tech note/test report) when closing the ticket.
It is the responsibility of the DMPM to verify this is actually done consistently. I have to date not being systematically doing this but rather on a spot check basis.
I will update section 4 of LDMP-294 to reflect the above policy of epic verification. I will undertake to do that more systematically.