The guy was a programmer and if reports are accurate then he worked on the software for the baseband i.e. radio. You'd need to be an EE which specialises in RF if you wanted to do the antenna.

Alledgely the problem is only the signal meter that is displayed and not with actual reception.

Gizmodo sure know how to milk a story for all its worth. Are there enough updates on that story with an iPhone in various positions? As this is Gizmodo, the next update will probably say that its been confirmed that iPhone 4 has 0 bars if you put your genitalia up against it.