The penalty incident was not blown out of proportion at all.
Before that game he was one of the most important players in the entire squad, since then he has been peripheral. Mirallas was always a starter in the team when fit and reintroduced back into the side as quickly as possible after injury. Last Saturday as an example he was left on the bench until the end , could you imagine that happening before the WBA game.
Will he leave ? I think it depends on what offers come in for him and from which clubs they come. I think Mirallas is happy at Everton but maybe he rates himself a higher than others rate him. I think he may stay at Everton if he doesn't fancy the clubs that show an interest, but I doubt he will sign a contract extension and leave in twelve months or for nothing in two years time.
In England, I think he would consider Spurs as the top four will not be interested in him and Everton are probably better than everybody else, he has already said he would like to play in Spain and that may be a preference.