In February 2017, it was reported that the sample of claimed metallic hydrogen (at Harvard) was lost, after the diamond anvils it was contained between broke.

High pressure researcher Paul Loubeyre of the Atomic Energy Research Centre for Military Applications in France, calls the new results 'much ado about nothing'. In particular, he sees no reason to believe that Dias and Silvera really achieved such high pressures. Earlier work, he says, has shown that diamond anvil cells can't attain pressures higher than 350GPa. 'It has been demonstrated that to explore the pressure domain above 400GPa will require new types of anvils,' he says. 'If you're going to claim that using a standard high pressure cell configuration you can obtain 50% higher pressure than previously, you should at least do a benchmark experiment [to prove it].'

Loubeyre also believes that 'the analysis of reflectivity is wrong – the correction for diamond absorption was incorrectly done'. He and his co-workers have explained their reservations in detail in a preprint.