Never, ever, ever, ever, ever ever believe any end user or any manager about data not needing to be backed up, or having already been backed up, or anything an end user says about any data.
Always do a backup. Always. Even if your manager says not to. Even if it is against company policy (just don’t get caught). Because like as not, your own manager will throw you under the bus as at fault when some exec goes haywire over missing data. I think every IT person in the world has learned this the hard way. I certainly did.
End users lie and are clueless. Managers are unreliable. Image that fucking drive before anything else. These days it only takes 10-15 minutes and could save your job.