Corrected entry: Sack finds out from his friend the true identity of John and Jeremy, but how's that possible? He gives his friend the names John and Jeremy gave him, not their real names. There's no way his friend could've found out who they were without their real names.
Xofer
1st Aug 2005
Correction: All Sack knew was that they weren't really the Ryan brothers; therefore he assumed, correctly, that they crashed the wedding. Considering the brothers seem to re-use some stories, it's conceivable that his friend found out their story was fake, hunted around, and discovered the truth behind it.
Xofer