Comment 2 for bug 1788556

Yes, it could be that there are items missed, I don't think it's fatal for the dhcp-agent. The only change I could think of to get past this is to trigger the retry code when we encounter a lease that's invalid. For example:

_read_leases_file_leases() see this < 5 case
  insert a "fake" entry to signify it

_release_unused_leases() checks for this "fake" lease
  if found, trigger a retry loop, which will read the file a second time

It's not that simple looking at the code, but could be done.