The fuel policy meets the regulatory requirements - as MOL keeps pointing out. However, the regulations can only stipulate minimums and if a company regards the minimums as a targets then any safety margins are eroded if everything doesn't go to plan - such as the Madrid diversions.
Technically, it's safe - because it operates within the regulations. When the circumstances dictate, human intervention in the form of airmanship should make the operation watertight. However, the documentary asserts the RYR Captains are being pressured into taking flight plan fuel, or a value very close. Of the three aircraft which diverted that night, none had much more than 300Kg over flight plan. I would say in those circumstances, it was less than prudent to carry such little extra and the result was that safety was seriously compromised.