Staccato Slide latch broke in transport?

[Austeyr]

I sold my Staccato on here over the weekend, I won't mention the buyer for obvious reason however today they informed me they received the pistol and the slide catch had snapped off. 

 

 

I checked the pistol on the 31st (Sunday just gone) when taking photos to list it, including taking the slide off and showing a photo (below) of the slide and the pin was in one piece, no damage (The pistol has been owned by me since new and had half a mag put through it on the day it arrived - Since then it's sat in a glass display case with my other pistols)

 

The pistol was sent in its original box, with all of the original packaging foam to secure it:

Screenshot (Above) taken from Jaeger's unboxing to showcase the foam. 

 

The buyer has confirmed the box arrived undamaged so it's unlikely to be from ParcelForce booting it around, so I come to you people for suggestions on how this piece could have snapped in half? The buyer said he pulled the slide back, the slide fell off and the pin fell out. I would love to work out how to avoid this in the future if/when I sell another Hi-Capa style pistol 🤔

[novioman]

Mmmmmm!