-- quick and dirty words of wisdom collected over the years --
If you say "I'll take the gig for (fill in inspectable item)..." and then follow it up with "... Someone and I did (this much of it) but we didn't do (the rest of it)" then all you've done is rope someone else into what you ciaimed was "your" gig. If you take responsibility, take it all. Otherwise, just say "I told this person to do it and they didn't."
your thoughts always welcome in the comments below!