Yeah I vote for "discovering teh receipt" as well. And maybe offer to take it in FOR him so that he doesn't have the personal info that's on it, if that srsly has you concerned? It would be a schlep but...??
And in answer to the original question, I am a horrible dreadful no-good very bad abominable no-talent liar. Gave it up as a bad job years & years ago. Only one exception to that: When it comes to my kids, if it's necessary for their health and well-being, I can lie like no tomorrow. Usually cause I'm so angry that I couldn't care less if the person(s) ever did find out, cause they're triflin' no-account trash to put my family in jeopardy. Fkn Grrrrrr.
But those occasions have thankfully been so rare as to not even be much of a blip on the screen.
Otoh I've no difficulty at all witholding info from folk who need to MYOB. I don't lie, I just don't tell.
Sorta the "We don't lie. However, the truth is not for everyone" philosphy.
Anyway good luck w/the compy situation.! Caveat emptor and all that