In Apeldyn Corp. v. AU Optronics Corp., C.A. No. 08-568-SLR (D. Del. May 25, 2011), Special Master Poppiti recently addressed a party’s failure to disclose five prior art references until it filed an expert report four days after the opening expert report deadline. Id. at 6. Although Special Master Poppiti found that the failure to timely disclose these prior art references was neither “substantially justified” nor “harmless” as required by Fed. R. Civ. P. 37(c)(1), he stated that, absent a showing of bad faith, the appropriate sanction was not a striking of the untimely expert report. Id. at 6-13. Rather, the Special Master found that the appropriate sanction was an award of the costs and fees that the plaintiff would incur in responding to the late-filed expert report, along with the costs and fees incurred in bringing the motion to strike. Id. at 13.