First off, the system is too low-powered for the antenna to even begin to be part of the problem. The 30-pin connector has been at the bottom of the iPhone and iPod Touch for years now, and more than one has had an issue over the years--usually with either the battery shorting out or something else in the case. Again, they antenna has nothing to do with it.
Now, if you're an electronics engineer or engineering technician like I was, then perhaps you can explain to me why you have this belief.
Looking back at the supplied images, I can think of one other reason why this might have happened--what if the connector was forced in backwards?(upside down, if that's the way you want to look at it.) By forcing the connector, you might feed the charging current into a low-resistance circuit which would very quickly overheat the wires. If so, then the fault could be the user's.
Yes the system is low power in nature, but the antenna hen receiving data from WiFi or 3G, or indeed during a call, it receive large amount of energy from the base station which can cause spark, when you have an antenna that it is open on the phone frame.
You can track on fire accidents that happens with other phones.
My advices are not to use the phone for calls while it is charging and with the iPhone 4 in particular to use the plastic cover, which isolates the Antennas.
I can not consume your idea that the user forced the connector to the limit that mixing of the pins can happen!! This is a strange argue that its the user's fault!!!!!