Can Apple Diagnostics be wrong about memory issue? I am looking for a second opinion on an issue with my brand new iMac.

I purchased a new iMac direct from Apple about 3-4 weeks ago, and initially everything was fine. However, in the last few weeks I've been getting an increasing number of crashes (particularly with Safari, but others too), as well as a few kernel panics (usually from Parallels). As it happens most with these two, I've been troubleshooting them trying to find solutions.

After a particularly annoying crash yesterday, I decided to run the Apple Diagnostics tool (hold D on boot), which told me there was an error with the memory (codes PPM002, PPM003 and PPM004). I duly contacted Apple who've gone through the basic steps like removing startup items, resetting Safari, etc and was told to let them know if the problems persist. Fair enough, but they seem to have ignored the Apple Diagnostics result, which is confusing me.

My question is this; could the Apple Diagnostics tool be wrong? Is it possible, or even usual, for it to report errors where there are none? I'm concerned that Apple support will lead me on a week long search for software issues (and perhaps even temporarily solve it) when the diagnostics clearly say it is a hardware fault.
Thanks
According to this Apple KB you have to contact them.
They should be willing to help because you have Apple Care the first 90 days for free and they state it on the site theirselves: