It really depends on Higuain. If we lose him to Arsenal, because he wants a big fat paycheck, and wages we can't afford, we can't blame Marotta.
However, if he wants to come to us (instead of going to a team that celebrates 4'th place as if they won a 500 million Euro lottery) and we lose him to Arsenal because Marotta is penny pinching over 2-3 million Euros, then Marotta should take the blame.