At the beginning of the episode, Natalie Manning sees a picture of her late husband and Jeff Clarke, he says that it was the last time they were deployed together. Now Capt. Jeff Manning was an U.S. Army Ranger, but in Chicago Fire S02E07 (No Regrets), Jeff Clarke says he was a "Jarhead", U.S. Marine, First Recon. There shouldn't be seen in the picture with the same uniform.
We know this episode takes place on August 1 because Dr. Choi is pictured writing the date in his journal, yet at a certain point, Dr. Reese asks her boyfriend, Joey, how the Bears are doing. The NFL regular season doesn't begin until the second or third week of September, and even the first preseason game isn't until the second week of August (August 11 in the Bears' 2016 schedule), so why doesn't Joey say something like, "It's not even football season"?