$70 Million in overlapping funds in the last decade is quite trivial actually. Let's just say they looked through NSF and NIH grants (though I think they included DoE and DoD and probably other agencies I'm not thinking about). In 2006, the NSF received 5.58 Billion and the NIH recieved 28.7 billion. Budgets have increased to some extent under Obama, so later years are more, but 2006 probably cuts it down the middle.
So 10 * (5.58 + 28.7) = 342 Billion
$70 Million / 342 Billion = 0.02% of total funding to these agencies. That is not 2%. That is 2 one-hundredths of one percent.
On top of that, as others here have pointed out, these grants come with fairly strict guidelines as to how they can be spent. These funds are not going into reseracher's pockets. They are not going to bonuses. They are going to research and university overhead. This pays for equipment, supplies, travel, and employee (and grad student) wages.
0.02% potential overlap in funding just doesn't concern me. Now let us go worry about something else, preferrably something of greater importance and impact.