They may have done a quick search, but not as thorough as one would expect finding buried cash.
If I found a wad of old cash buried just below the sand, I might think "what idiot buries his money like this?", I might even dig a bit deeper, just in case. But I don't think I'm in some kind of money burial grounds where wads of cash are laid to rest and all it will take to find more wads of cash is to dig in random spots up and down the sand bar. Hypothetically speaking, of course.
A "financially struggling" family finds bundles of cash in shallow sand and leaves within 2 hours never to return to search.. and they were there for a picnic, anybody think they would have even had shovel with them..
We dont know for a fact they or someone related to them didn't return to look for more cash. Others did. Cook claims others had found parts of bills on the sandbar months earlier... he claims to have witnesses.
We are talking about a very tight time frame here.. from 3:30 Sunday to Monday evening.
Between the 3:30 Sunday money find and contacting the FBI Monday their search would only have been very superficial.. at best
They found the cash at 3:30 Sunday on a picnic, do people bring a shovel on a picnic?
Brian said they searched for more, I believe him.
Did they have a shovel, if yes that is odd for a picnic, if no then they searched by hand >> superficial
They left within two hours of the find 30 minutes before sunset, how long did they actually search, did they ever build that fire?
Brian claimed his parents said it was probably "counterfeit".
However, by Monday Dwayne claimed he thought it was mob money or lost, he had called a bank so they knew it was significant and had value.
So, at this point why didn't they return, maybe with a shovel to look for more. They didn't, instead contacting FBI Monday evening.
You find cash buried on a sand bar, you know it has value and don't do an adequate search before calling the FBI the next evening. That goes against human nature, unless Dwayne knew there was no more money there.