Character mistake: Meredith admits during the ethics seminar that she has been sleeping with Bruce, the HammerMill rep, for discounts on paper/paper supplies for the company, as well as Outback steak coupons, for 6 years. But, Dunder Mifflin did not begin selling Hammer Mill products until 3-2 "The Convention" when Michael got the contract.
Character mistake: At one point in the show, Roger throws a bucket of water (in disguise as Scotch Bingeington) on Francine claiming "Wet T-Shirt Contest!" Francine looks disgusted when Roger states "Eh, give this one a four" to the guy judging the contest, then says to Francine "Don't feel bad, you've had three kids." Francine replies "I've had two." and Roger gasps and puts a consoling hand on Francine's shoulder. This is wrong because Francine has birthed four children. She previously gave birth to Bailey (Hayley's twin), and Greg and Terry's baby in Season 3 Episode 7 "Surro-Gate." (00:14:15)
Character mistake: When talking to a family, Christina says that the patient had "hematomachrosis" instead of "hemachromatosis"
Farhampton - S8-E1
Character mistake: When Barney is telling his story to Quinn in a minute he says, "Ted and I stopped being friends, Ted got hit by a bus, we made up." Barney got hit by a bus, Ted got hit by another car. (00:12:10)
Charlie and Dee Find Love - S8-E4
Character mistake: Near the end, when Charlie is leaving to be with the Waitress, Ruby says she wasn't using him "like Charlie was." She's talking about her brother and meant to say "Trevor."
Character mistake: While filming the cheerleader performance, Jasper refers to his inability of using computers ("We're gonna put this on YouTube as soon as one of us figures out how to use a computer!"). Earlier in the series, however, Jasper ordered himself a Russian wife online, so this statement is definitely off-character.
Suggested correction: Michael didn't establish the contract with Hammer-mill. Rather, he locked them up as an exclusive supplier. It's unknown if they were already selling the products to Dunder Mifflin alongside Staples and Office Max.
Wrong, Josh says they cannot sell Hammer-mill products as they are exclusive to Staples so therefore they wouldn't have been able to sell there products alongside as mentioned before until Michael made them an exclusive to them solely, Dunder Mifflin. Therefore the original mistake stands true.