It was a bad management from the referee yesterday night.Roma played better until the point Dybala was out for that Netherland attacker which was the worse player of the whole match in my opinion.The referee missed two clamorous penalties for Roma and one for Sevilla and the bad thing was that he kept saying "No penalty,no penalty",I wonder why UEFA let Premier League referees in such finals,they are not fit for when two teams of other nations play each other as they are used to another type of football in the Premier League,I am not saying they should not manage a final but not such type of referees who made the game go a different way.
I agree with you that they shouldn't use that kind of referee in a final because both teams will be focused on winning the league and will do whatever it takes to do so. Roma was very serious in the game yesterday because they knew Sevilla had the desire to win the Europa League. The first goal convinced me that Roma was fully prepared to defeat Sevilla; the only thing Sevilla has was luck.
Roma really played well, and even Sevilla will believe that they just got lucky to win the game, therefore it is not terrible that they didn't win the game since the game is either you win or you lose.
Any football match is a stroke of luck. Especially it's a final and only one game instead of two. But I think Sevilla have played very well this season. They had really strong opponents, unlike Roma, who got to the final much easier. Therefore Sevilla's win is fair. Roma had their chances, but Sevilla were lucky.