Man, I'd be worried to the point that I'd probably replace all 20 studs. It would bug me until I did.
Whoever thought 5 lugs was better than 6 at Toyota should have to replace these for you. Not that a few percent less load on each can solve a numbnut overtorquing, but losing two of 6 would worry me less.
'91 Toyota Pickup
'09 Kawasaki KLR650
'12 Gunnar Rockhound 29
“Anyone who believes in indefinite growth in anything physical, on a physically finite planet, is either mad or an economist.” -- Kenneth E. Boulding