Continuity mistake: The time on the mantle clock behind the man carrying a shovel (as a weapon) changes several times, jumping forward or backward (e.g. 6:50 to 7:18 and 7:18 to 6:43). The clock behind Adam is sometimes coordinated with the other clock (@ 7:48), but other times is not (e.g. 7:52 vs. 7:18 or 6:43). (00:21:08 - 00:22:17)
Continuity mistake: Before going outside with Alex to meet the crowd, the knot in Henry's tie has one diagonal white (or light-coloured) stripe showing, which is near the centre. When Henry opens the door, there are two stripes showing on the knot - one near the top and the other near the bottom of his shirt's collar. (01:45:40 - 01:46:35)