"In your big tourny's, does anyone check that the value in color coming back to the 'cage' is the same (near enough) as that which was taken out?"

We only put enough large on each table to take the small off.
In the case of $5 or $25 coming off, one stack of large will do it. There are times when a dealer will need 1 more large chip. In a small tournament the dealer handles this and it is hard to make a mistake as he don't have the chips to make a mistake with.

It would have to be handled by the floor with 86 Mil on the tables.
Yes, If I was doing it there would be a count in and out of the cage.
If there were 3 tables with 86 Mil, an eyeball count would tell the floor how much large he needed to take out. Or a cage count should tell him how much small is on the tables.
I don't understand how this mistake could have been missed.
I guarentee if Phil Gordon had of been watching it would not have happened.
He can count stacks faster than I can say "time to color up."
Tuna is the fastest chip counter I ever seen.
Example:
15 tables 200 chips to start with mulitpul rebuys, double chips for last rebuy.
Toury director announces break. Runners start back in with re-buy $. Tuna stands up, eyeballs the tables, yells out 38,400 chips in play.
The 1st runner has yet to have his $ counted.
Results after count, 38,400 chips.