Character mistake: Frank implies that Joe is the oldest child, but he was born in 1977 (1x22), Erin in 1975 (6x07), and Danny 1973 (2x17). Erin also claims she wasn't born yet when the murder of Henry's friend took place in 1977 but she would have been about two years old.
Character mistake: Throughout the episode they refer to the victim owning a "cement" company. In fact it was a concrete company. Although the terms cement and concrete often are used interchangeably, cement is actually an ingredient of concrete. Concrete is basically a mixture of aggregates and paste. The aggregates are sand and gravel or crushed stone; the paste is water and portland cement. (00:00:05 - 00:35:50)