One thing I learned in my tournament was to bare in mind the "consderations" when choosing whether a tackle is "careless," "reckless," or "using excessive force:"
1) Did the play have a fair chance at playing the ball? Yes, he did.
2) Did the player put his opponent in a dangerous situation? Yes, he did.
3) With which part of the body did the player make contact on his opponent? The studs.
4) On which part of the opponent's body did the player make contact? The shins.
5) Did the player "far exceed the necessary force" when making the challenge? I don't know that he did; he started from a standing position and didn't take a long running start therefore necessitating the jump.
All in all, with these considerations in mind, I'd say it's a caution for USB as the player committed a reckless challenge.
