Maybe he got an interline discount but looks like the fine at AMS for drunk FO's at AMS is less than a couple of years ago:
Drunk co-pilot arrested at Schiphol airport
By Janene Pieters on May 11, 2015 - 11:04
A co-pilot who was under the influence of alcohol was arrested at Schiphol airport on Sunday morning.
NOS reports that the man was about to board a plane that he planned to fly. The aviation police and marechaussee, military police, checked the man after receiving a tip.
They quickly realized that the man had been drinking as his breath smelled strongly of alcohol. A breath test showed that the man had 375 ug/l alcohol in his blood - well above the maximum allowed amount of 90 ug/l.
The man flies for a foreign airline. He received a 15 hours flight ban and a 6 thousand euro fine.
Drunk co-pilot arrested at Schiphol airport | NL Times