Well that part was specifically after the Part 2: Battle Tendancy FIN message. There was nothing after Part 1's FIN message.
Seeing how loyal they're being to the adaptation, they wouldn't have put that part after Part II FIN if it was in Part II [On the other hand the Joseph kicking the Japanse person was before the FIN, so may have been the end of the manga.]
IDK for sure, not read Pt II.
Also Joseph in that airport part looked a ton different from OVA Joseph.