Looking at the photo again; hasn't that been installed on the wrong side of the non-return valve (yellow bit)?
Never seen the instructions for one of these, but I'd have thought it would be better on the other side of the valve, so as to not affect the vacuum level in the servo if it malfunctions? 
Well spotted !!!! Never really thought about it, it should be fitted as you describe, best plan is probably just to take it off all together and replace the original hose with a complete one.
Agreed. You'd be better off chucking 50 quid in the bin than buy this tat
