I don't know if David Nalbandian is a jerk, but kicking an unsuspecting, old line judge kind of seems like a jerk thing to do.
Here's video of the kick which got Nalbandian disqualified from the Aegon Championship men's singles final.*
*SB Nation and its editors must insist that no one attempt to recreate or re-enact any kick or activity from this video, whether or not it's explicitly forbade by the ATP.
I prefer this video context-free, but if you want here are the details from the Guardian:
Having just lost the seventh game Nalbandian fiercely kicked an advertising board in front of the line judge Andrew McDougall's chair. The board smacked into the line judge's shin and caused an inch-long bloody gash.
The referee Fergus Murphy then awarded Cilic the match, and the championship, disqualifying Nalbandian for "unsportsmanlike behaviour".
Nalbandian was apologetic for his actions, going over to McDougall but following consultation with the ATP supervisor Tom Barnes, the match was abandoned.
The crowd booed and chanted "play on", but the decision was final and Cilic was handed the trophy.
Nalbandian was upset with the decision but come on, dude.