What could've caused damage on tyre?

[Noneking]

Metzeler 190/55 17 rear tyre on BMW K 1600 GTL - 8000km
Puncture was repaired at 2000km

This is a patch of about 15-17 cm. Rest of tyre in excellent condition and looks like still a fair amount of tread left.........
Bike has tyre pressure monitor and I've always had it between 2,7-2,9 bar

 

[ETS]

 

[Chrisl]

 

[Piston Pete]

 

[Noneking]

 

[Dwerg]

 

[Jughead]

 

[Noneking]

 

[Piston Pete]

 

[Noneking]

 

[BFG]

 

[Jughead]

 

[Barryc]

 

[Noneking]

 

[BFG]

 

[Crunchie]

 

[Moondog]

 

[Noneking]

 

[macjohnw]

 

[Draadwerk]