Continuity mistake: The house number is 6101 but 6301 is on the step leading to the sidewalk/house. Later, when they are moving, the house number is 6301 and the number that was on the sidewalk is some kind of indiscernable pattern (not distinct numbers). (00:02:20 - 00:08:34)
Audio problem: After the liquor store clerk says, "I can't read this", his mouth does not move when he says, "Hey." "This is not you" is off-camera, then his mouth movements are back on track. (00:55:00)
Continuity mistake: Bill's driver's license/ID is next to the first $100 bill the liquor store clerk counts (sets on the counter), but when the clerk counts the fifth $100 bill, the driver's license is no longer there. The clerk hands Randy the $500, then says, "Dont forget your dad's ID" and hands it to him. (00:55:15)
Character mistake: When asked if he had a job, Mason Sr proudly responded he just happened to have passed his second actuarial exam and that's what Mason could tell his mother. Mason Sr didn't seem to realise the first two actuarial exams are the easiest to pass, many aspiring actuaries have completed the first two exams by the time they earn Bachelor degrees, and will study for years for the remaining exams while employed full time. He wasn't anywhere near being an actuarialist and wasn't employed - yet bragged. (00:39:44)
Other mistake: Mason Sr spends time with Sam and Mason every other weekend. After going to the Butterfly Center, they tossed a football and ran around (playing tag?) a while before going to the Houston Astros vs. Milwaukee Brewers baseball game. The limited footage of the game in the movie (which included Astros #16's home run) was adequate to identify it as the 4/17/06 game that started at 7:07 PM... on a Monday (not over the weekend). (00:39:45)
Continuity mistake: It was daytime when Bill took the kids to the ATM and questioned them regarding Liv's whereabouts. When Liv picked up the kids and was backing out of the driveway, the sun was setting behind the house. As she drove down the straight road (she didn't make any turns), the sun was shining brighter and then some of the trees on the opposite side of the road cast shadows in the direction of the sun SETTING. (00:56:53)
Continuity mistake: The campfire's distance from the tent does not stay the same. When Mason and Mason Sr are roasting marshmallows and making S'mores, the campfire is close to the tent. Overnight, the campfire looks about the width of two tents away. In the morning, the campfire is close to the tent again (less than the width of the tent). Mason Sr's boots are outside of the tent in the morning, but he did not wear boots when walking through the woods the day before - he was wearing brown (hiking?) shoes with black trim and laces. Mason Sr's clothes also change from walking through the woods (t-shirt and shorts) to evening (red/gray checked shirt and shorts) to morning (red/gray shirt and jeans). During this time, Mason's clothes stayed the same until morning when he put on a different jersey. (01:10:27 - 01:11:40)
Continuity mistake: The art/photography display at UT and the background change a few times when Mason is removing his photographs and talking to the woman. The photos along the right side of the display disappear. After Mason removes two of his photos, it doesn't look like the third one is still posted, but after the woman leaves it is visible. The backside of pictures show up through the metal display some time after Mason removes the first two pictures (but were not there when he first removed his pictures). A lot of people are moving around in the background when Mason and the woman are talking and two girls in blue shirts were there the entire time, but when the woman walks away the people in the background are gone. (02:10:44 - 02:11:50)
Answer: She is divorced from the dad. When Mason's mum leaves him with her kids she says that she has contacted their mother and child services.