If a mistake is made and your signature is on the proof, you will be on the line for a full reprint. Make sure you have sign-off authority before sending it back. It's not uncommon for a job to be pulled at press because the head of marketing hadn't seen the job. Keep on deadline. If your printer says he needs approval by 9 am, you can't send it back at 5 pm and expect to stay on deadline.
Paper needs to dry, a press needs to go through make-ready.
If you're going to get behind, expect your project to get behind. If you encounter a bad link please email me and let me know about it.