That's fair, but in this case it should be pretty easy to verify if the person is lying. The claim is highly reproducible and the instructor wouldn't even have to do it.

It's only "reproducible" if you find other 555's mixed in the shipment but not distributed to students. Depending on what the error rate in the shipment packing is, that might be very easy or it might be quite hard. At any rate, it's a stats problem that the professor is unlikely to want to engage with. Unfortunately.

For the next semester, a good prof would have a QA step or a harnass that turns on a green light if you plug in a working-as-expected package. I can see how the lab assistant job gets plenty to do in a well-run course, and also how unlikely it is to be happening in real life. There aren't enough incentives.

I suppose, although if the student is able to show the prof with the tools that the chip they have (which based on the story should be visually identical or very similar to the rest of the chips) behaves incorrectly, that test can be repeated many times. It's possible the student could have acquired it elsewhere and is snowing, but even if that's the case the fact that they can do the analysis and show (and waited so long in the class to get there), and have the history of asking for help throughout the course, all add up to pretty powerful evidence IMHO. The prof could even do his own test with the chip if he doubts. It seems hard to believe that one student would intentionally try to "cheat" by making his life much, much harder. It's surely a path of much less resistance to just follow the book.

How? What happens when students start buying faulty hardware to justify unrelated delays?

As a teacher, my first rule is, be kind. Sure, there are people who will take advantage of the situation, but they are not really taking advantage of me.

In this case, I'd have a harness that ensures the parts they were given work as advertised, and make it the students' responsibility to report within the first 3 days if it is not working.

Yes, although just having the faulty hardware isn't enough. They also have to use the tools to show that it behaves incorrectly, which is surely a lot more work than just following the book would have been. That is the part that is easily reproducible. The student already knows how, so in a few minutes he can set it up in front of the prof and show him. The prof needn't do anything other than watch for a few mins.

If more of these cases crop up then you should get suspicious, but you also need to consider the impact of giving a student the wrong chip and expecting them to succeed! I think Blackstone's Ratio should apply here personally

Unfairness to the class, if kept under wraps, is a case of no one actually being harmed.

Translation: scammers get the green light.

But OP wasn't a scammer.

The problem: it won't stay under the wraps. People talk. Feels shitty when the scammer tells everybody how easy scamming was, when you yourself worked through the night to finish your assignment.

Note that AI provides a whole new range of possibilities for automating lying about assignments.

Option 3: treat your students like adults as much as possible and be flexible with everyone about how they complete the class as long as they demonstrate that they've done sufficient work and have sufficient mastery of the material. Then you don't need to play arbiter about whether having a child in the hospital is a better excuse than having their backpack stolen, and you don't unfairly favor squeaky wheels over meeker students.