SFP and media converter test

I didn't expect the following to work, but it does.....ish and with limitations. Above anything I am wondering why I am getting the specific error that I am in regards to the following scenario.

I had a cabinet hit and used our last spare industrial switch (we had already put in an order for more), but I started looking at piecing together an option in case we had another issue happen in the next week or two. Here are the spare parts I used in this test:

• Cisco 2960 with 2G ports and 24Fa ports.
• Cisco 2960C with 2G ports and 8FA ports.
• Media converter 10/100Base TX to 100Base FX (2km multimode)

I connected the RJ45 from the media converter to fa0/2 on the Cisco 2960C (100 to 100) and the fiber ports to a 100Base-FX SFP in the G0/1 on the 2960. I did not expect traffic to flow being that the G0/1 port isnt(??) supposed to downgrade itself to 100. Traffic flows though. I haven't tested the limits of the bandwidth, but consistent pings. I do get the following error though: duplex mismatch discovered on GigabitEthernet0/1 (not full duplex), with Switch FastEthernet0/2 (full duplex). This is odd to me because both sho interfaces still show full duplex. Why is this the error being generated instead of something in regards to a 100 in a 1000 slot?

On top of that, when I throw an industrial switch in between these two, it still gives the same error acting like the other switch isnt even in existence: 2960C Fa0/2 -> media RJ45, media 100FX -> industrial 100FX -> industrial 100FX -> 2960 G0/1.

I am not planning on utilizing either of these scenarios in a production network as is given the errors occuring, but I am trying to figure out why they are acting the way they are instead of just shutting off.