The US National Transportation Safety Board has not ruled out age or service issues in its investigation into an ⁠incident during ⁠which a passenger was partly sucked out of a broken window on a Boeing 737 ⁠NG Ryanair flight from Greece to Germany, Reuters reported.

Wednesday’s letter contradicted claims made by Ryanair ⁠CEO Michael ‌O’Leary that initial findings indicated the window was damaged by a “foreign object.” ‌He also claimed the incident was not linked to the aircraft’s age or servicing conditions.

“The NTSB ​has not made any such determination,” Reuters reported NTSB ‌Chair Jennifer Homendy as writing ​in a letter to O’Leary.

Homendy also said O’Leary comments violated ‌the agency’s rules ​on disclosure by parties to the ‌investigation, according to Reuters.

Ljubisa Karovic, 61, was partially sucked out of the aircraft after the window next to his seat shattered shortly after takeoff from Thessaloniki in northern Greece on July 10.