-- Qwiss is right about the xG, but it's a bad metric for assessing whether Martinelli wasted a good chance or not. The criticism I've seen on here has been that he should've taken the shot first-time or taken his first touch differently.
xG just looks at the chance of scoring from the exact still image when the ball was struck, it doesn't say anything about whether he could've done something else instead. The xG being 0,084 just tells us that if you take the first touch Martinelli took and then shoot, it's not a good chance.
