Chris's Mother and Other Minor Issues for Season 10
I guess the writers forgot that Chris got compassionate leave to attend his mother's funeral back in season 5, episode 6 ("Dead Loss"). It was a bit of a surprise when she showed up alive and well at the party in season 10, episode 6 ("Blinded by Love").
It's slightly less of a contradiction that Chris already asked Sharon for a divorce in season 8, episode 5 ("Can't Judge a Book"), when he wanted to marry his jail visitor, who was the same type as Sharon. I guess the paperwork for the earlier divorce could have fallen through or he changed his mind. Still, it made "Blinded by Love" seem rather like a retread of the earlier plot.
I'm not sure why they had to recast Garth so much younger or suddenly replace his wife and child from the end of season 9 with unrelated characters from Australia. The character was at least 22 when he got married to the girl with the bun in the oven in season 9, which means he should be at least 38 and should have a child who is the same age as his brother. Obviously, the previous family could have been explained away with a quick line about a divorce, but they didn't bother.
Oh well, in spite of the annoying little plot details, it is fun to see the three main birds back together again!