After the draft, Belichick said a few cryptic words indicating that there WERE players he was interested in trading up for, but the teams in question weren't willing to trade down. Note that no trades took place in the 6 spots leading up to the Patriots' pick, a range that included J.J. Watt, Nick Fairley and Robert Quinn as well as Kerrigan.
As for Solder, early results suggest they may well have gotten the single best player left on the board at #17, a guy who both filled a need at a top-value position (remember, Light was unsigned) and has mammoth upside. And at #28, consider that NOT ONE edge rusher was drafted between 28 and 33, so who did they miss out on?
IMO that leaves one solid edge-rusher complaint: passing on Jabaal Sheard. And I have to admit, even though I might have been the biggest Dowling fan on the board, Sheard would have been my pick at 33.