If the IDC numbers were so dramatically off for tablets, how can we be sure they were accurate for the phones?

According to their Q1 2012 numbers for Samsung Android smartphones, 40.8 million were shipped. (source) According to the court documents, 2.5 million were sold in the US. (I'm picking Q1, as the court documents lack Galaxy S III sales for Q2). Even with phones, we have a massive discrepancy.

40.8 worldwide, 2.5 US would put the percentage split at 93.9%/6.1%. That still makes no sense.