You wouldn't know if it was under the table or if it was non-monetary favours such as promotions for friends/family working at Meta or the implied promise of a nice high-paying position once they're out of the DPA role.
It could also be corruption at a higher level - the only reason Big Tech likes Ireland is because it's somewhat of a tax haven and accommodates unlawful practices like this one - if they stop being accommodating the companies will leave, so there's an incentive to not piss them off too much.
