Howard Webb, who reffed the 2010 final says no penalty.
Webb says no penalty.
That should convince everyone it was a penalty.
Frankly, people should watch the replay again. Perisic goes full handball mode, lanches his hand towards the ball as Matuidi misses his header.
Anyway, I remember vividly, right after the 98 final, I drove back home and changed the radio stations, and somehow wanted foreign opinions on it.
I tuned to BBC.
And what I heard is sill to this day a fond memory. English "pundits" saying how France didn't deserve to win, that it was the worst WC final ever (remember, the previous WC final was 94 ! ), etc...
So if english pundits are saying it was not a penalty, it's not highly surprising, and maybe some people need to change their source of information if they can't make their opinion by their own.