"Yes, I think those were the only two choices. Work alongside them, or laze about their house without supervision. Since this is a kid needing supervision, lazing about the house is probably the best of the possible outcomes, with the alternative being getting into trouble.
I guess there is a third. For the summer, abandon the expensive project that they started before they were asked to watch the kid."
They could work half days, or alternate days, so he's not doing the work we'd normally expect of a paid adult all summer. They could work for a week and then do something fun for a week so the boy's whole summer isn't buried in hard labor. They could postpone the work rather than abandoning it. They could bring him to the flip house but not make him work full days every day for months. There are many, many options on the continuum beyond the three you presented and it didn't take that long to think of them. This kid is twelve.
Library Dragon wrote:
"It's not unusual today for teens to be working on family farms during harvest time. In high schools in my county it's common for teens to be out for a week or two in October for cotton or soy bean harvest. It's the family business and everyone pulls their weight."
How many of those high school kids are twelve years old? How many of those teens walked away from their own family farms to work full time jobs for someone else for no money? That's what happened here. We're not talking about "the family business" here, because this is the first house they've flipped in nearly a decade, so one could hardly call it their bread and butter. He's not "pulling his weight", he's pouring adult levels of effort into someone else's hobby without any reasonable way of avoiding it.
"Can you imagine a 12 year old boy's delight at being told, "Here's a hammer. Go for it.""
Can you imagine how that delight would wane after three or four hours of it? How about weeks? There's a reason why adults have to be paid to be willing to do this kind of work for others.
"We have no way to know exactly what the teen in question was asked to do. He could have been at the job site all day, and yet not doing adult-grade work."
CoCoCamm wrote, "Oh and when I said Tween was used for free labor I mean hard labor. Demolition and it's resulting clean up, putting up sheet rock, laying down floors, acting as an apprentice for electrical and plumbing work, patching up the roof, etc." I don't see any reason to disbelieve her in this. And as I keep having to point out, this kid isn't a teen. I find that people seem to be taking the mental image of some slacking fifteen-year-old, but this kid would have just finished sixth grade.
"As for injuries--my DD hurt her foot in a sports activity--it may dog her the rest of her life."
There's a big difference between sustaining an injury during something that you've actively asked to do and during something that you're made to do without your consent.