"The Treasure of Sierra Avenue" note

[James]

When the boys were counting the money they found in the wallet, there were three piles of bills. Previously it was specifically mentioned that the money was mixed with $10, $20, and $50 bills. At first glance, it would appear that Greg had them separated into $10, $20, and $50 piles. However, when Greg places some bills down, he puts them on different piles ("... $900, $950, $1000, $1050, $1100."). Translation: All the bills we saw him lay down were $50s. Wouldn't it have been more wise to place the $50 bills in one specific pile to separate them from the $10s and $20s?

(Come to think of it, I think Greg placed 3 or 4 of the 5 $50 bills in one specific column! So could that have been an error on Greg's part by not placing the same denomination in one pile?)