Dell through disk diagnostics instantly passing

I've seen this behavior on a few machines before and I'm trying to understand why its happening. I run the Through Disk Diagnostics in the Dell Support Assist Pre-System Performance Check and it instantly reports back as Passed without actually running any diagnostics. The user's Windows install was corrupted and I was able to re-image the device but I'm warry of giving it back to the user since I cannot actually determine for sure if the SSD it good or not. Has anyone seen the diagnostics instantly pass a drive without doing diagnostics before? What does it generally mean when it does that?