copper infection?

[majo]

Last I've had a client running his 2008 altherma in cooling mode. The thing went fine until last week, suddenly wasn't able to reach watertemps lover than 19°C.
Went over there, SH 22°!!!
Reclaimed refrigerant -> 0,9kg instead of the stock filled 3,7kg!

Pressure tested the unit and found a leak in the 5/8" suction line about 40cm away from the indoor unit.
It was a quite large hole in a bent with a radius of about 20cm (slow), nothing special...

I'm a bit shocked that this could happen to a copper line installed about 1 yr ago!?!

Did anyone come across this? I'm standing a little negative regarding the copper used and I'm wondering what brand of insulated copper you guys often use?

Are the twin tubes from armaflex, inoac, ...any good or did someone had a problem like this with any of these?

kind regards