Anything that can happen will happen, and because the manual is finite, eventually the will be a situation that the company is unprepared for.
Take responsibility, yes, but don’t act beyond your authority. Tell the person that you’ll find out, and ask the appropriate person.
If there is time pressure, don’t take on more than you can reliably handle - don’t take info and promise to contact the person unless you can do that. It’s always better to give the person contact information and ask them to call or come back.
For years companies loved “I can” statements. “I can help you with that”, “I can find out for you”, etc. But I think that might have fallen out of favor, check with someone younger than me (lol!).