Corned beef is so named, not because of the grain "corn" (maize), but because of the method of preserving it. Large crystals of salt were originally known as "corns," as were the crystals of saltpetre, each of which were formerly used in the preserving process.
Many of the episode titles are also the names of or lyrics from songs; "too good to be true" is the majority of the opening line of "Can't Take My Eyes Off You" by Frankie Valli.
After this episode, Tommy Rizzoli isn't seen until near the end of the series (season 7, episode 11.) During that time, it isn't mentioned where he is, but when he reappears, he makes a statement indicating he was in Chicago with Lydia and T.J.