Climbers are a good tool to have. An alternative to a pop up blind is a roll of camo burlap. It might take a little more time to set up, but you should be able to brush it in pretty well.
I'm wondering if the other guy even knew you were there. It doesn't make sense to set up that close. I had a guy do that last year during gun season. He looked right at me before plopping down on his bucket. Out of spite I kept moving around, coughing, and I even made a phone call. He soon left. I had a horrible toothache, so I was not in the mood for some jackhole to come near me. It was opening day, so a toothache wasn't gonna' keep me from hunting. The phonecall was to my fiance telling her to schedule a dentist appointment.LOL
Back to your question. The burlap is inexpensive and you could take your nephew the day before you plan on hunting and show him how to set up a blind.
Good luck