No, but it is if you then follow through and plant six studs on your opponent's shin. Would have been an excellent challenge 10 or even 5 years ago, but not allowed now.
He didn't follow through any more than it's physically possible not to and Forestieri ran into him with little chance of getting the ball. I'd prefer to see an honest challenge like that than Forestieri's cheating any day.
If that tackle is worthy of missing 3+ games of football, I despair for what the game is becoming.