Perhaps I should have asked you a much more direct question.
The researchers got a conclusive result that showed that there were much more helium atoms present than should have been for a given constant rate of decay and the measured rate of escape from the crystals. Now since the concentration of helium inside the crystals were much higher than outside and the crystals were intact[meaning that helium [or Uranium, Thorium and lead for that matter could not have come from the outside], just what conclusion would YOU have drawn from the research data?