Preparation is your greatest tool to avoid problems caused by difficult or agressive
attorneys. Ultimately, once you are at the deposition there is little you can do without risking
sanctions. Harassing behavior. If an attorney engages in ongoing harassing behavior which
is truly beyond the pale, call the magistrate of court and have a discovery conference. However,
make sure it is truly exceptional. 

 As mentioned earlier, your best tool to control the deposition is to prepare your expert. If
truly extraordinary harassment or name calling occurs and persists even after you have addressed
it on the record, and the Court is not available to resolve your dispute, you can move to terminate
the deposition. Rule 30(d)(3) of the Federal Rules of Civil Procedure allows a litigant to suspend
a deposition at any point for the purpose of filing a motion to terminate or limit the deposition on  the grounds that it is “being conducted in a manner that unreasonably annoys, embarrasses or  oppresses the deponent or the litigant.” Obscenity or insults, persistent questioning that  embarrasses a witness or concerns privileged matter are sufficient grounds for suspending or  terminating a deposition. See Redwood v. Dobson, 476 F.3d 462 (7th Cir. 2007); Lewis v. United  Air Lines Transp. Corp., 32 F. Supp. 21 (W.D. Pa. 1940); Broadbent v. Moore-McCormack  Lines, 5 F.R.D. 220 (E.D. Pa. 1946); Shapiro v. Freeman, 38 F.R.D. 308 (S.D.N.Y. 1965).  

If a suspension is sought, the deposition remains postponed until such time as the court issues an
order. The loser is subject to fees and sanctions under Rule 37(a)(5). Smith v. Logansport Community Schools Corp., 139 F.R.D. 637 (N.D. Ind. 1991).