Cutting to the chase:

a) You have demonstrated, in a public forum, that you fully understand the situation.
b) You also demonstrate that you understand the code.
c) You also demonstrate that you know that the situation is not up to present code.
d) You also demonstrate that you understand that by plugging in a second large-use device, you are creating a risk, albeit a very small one.

Feigned ignorance will get you nowhere should that risk manifest. You might not like it, but the other principle of assigning liability is called "Last Clear Chance". Which you also demonstrate as having, clearly.

https://dictionary.law.com/Default.aspx?selected=1107

Peter Wieck
Melrose Park, PA