As the crew gets out of the van, the director says there is no cell service in Holmes county. In fact, there has been reasonably good cell coverage in Holmes county for years. Some sects even allow / encourage cell phones (solar charged, not connected to the 'grid').
Black bonnets and bonnet caps are considered more formal, and only worn on the Sabbath or special occasions. White is for everyday wear. Bonnet caps are also supposed to be worn covering the ears at all times, and are not tied under the chin. Because bonnet caps are pinned in place, the bonnet strings are usually left loose, or possibly tied with a small bow or knot near the ends.
They use short, square shovels with offset handles to dig up a grave. This would be extremely difficult to do with a square shovel, aka a "transfer shovel", which is not meant for digging, but for scooping loose things, such as gravel or sawdust.
Being on a farm, they would have known this and had access to proper digging shovels, which have pointed blade edges to cut into soil and long, straight handles to provide leverage to pry up dirt or stones.