It’s not quite irony.
The adverts where van Zanten appeared featured his commitment to punctuality. If you read the transcript or listen to voice recorder, it was van Zanten who appeared to get impatient and began the take off procedure prior to confirming runway clearance.
That’s not irony, that’s negligence.
The taxi way was blocked by the KLM on the fuel pad, thus Pan Am missed an opportunity to depart when the flight restrictions, due to a terrorist attack, were lifted. After the hour plus delay fog swept in across the airport at dusk.
Two overtaxed tower operators gave confusing instructions to Pan Am, per a taxi down the runway in trail of the KLM, instructing a turn off the runway which appeared would require a 135 degree turn onto a diagonal if it were the correct location. Pan Am was consulting the tower about the correct exit at that point.
KLM had no clearance for the take-off roll, the KLM co-pilot could be heard on the voice recorder stating the Pan Am had not confirmed being clear of the runway. The pilot discounted that possibility and commenced acceleration. KLM had taken a full refuel, therefore required a longer takeoff roll and could not clear the Pan Am still on the runway.
Dutch citizen Robina van Lanschot, working as a local tour guide upon Tenerife, survived as she refused to re-board the KLM. This wasn’t the proper port of entry; but, the fateful decision to go directly to her apartment worked to her favor despite the legal impropriety of skipping customs entry on Grand Canary.