When Lydia tries calling 9-1-1 for help, the operator refuses to send help because someone had previously warned them about possible 'prank calls' about needing help in the school. In reality, 9-1-1 operators are supposed to take ALL calls for help seriously, even if it's believed to be a prank. In instances where calls for help may not need actually assistance, ways to confirm a call can be ignored will be in place. Examples of this exception are sometimes mentioned in the show, What Would You Do? (2009).
Allison get's a text message from Scott telling her to meet him at the school URGENT. The time the text was sent and received is 7:12pm. But, her phone shows the current time as 9:26pm.