If the debris field of MH370 is similar and if Australians are looking in the right place right now or were looking in the right place at any point in the last two weeks, it's hard to explain whey they did not find anything at all so far.
The 'Occam' explanation would be that the aircraft did not come down anywhere near where they are looking.
Everything is being done on the basis of an estimated 'radar range' analysis of a Satcom 'handshake'. But a Satcom system is not a Transponder system. The reply delay on a transponder is very finely calibrated. The range information is extracted by subtracting the time of transmission from the time of reply, further subtracting the calibrated reply delay and dividing the result by two to get a very accurate measurement of the time the radio wave took to travel between the ground station and the transponder. From the time it took the radio wave to transit and the transit velocity (assumed as 'c') we derive the slant range. [Slant range - e.g. an aircraft directly overhead the ground station at 18,000 feet would show a slant range of 3.0 NM]
Unlike the precision of a transponder operation, Satcom reply delay during a 'handshake' is not finely calibrated to define distance from the satellite. The delay could be anything from nothing to a few hundred milliseconds, and we don't know what assumptions were used in calculating the two 'possibility arcs'. The true radial distance from the satellite position could be much different to the assumed distance currently used to direct the search. A slightly longer than assumed internal time delay could erroneously place an aircraft that was close to the satellite, as being several thousand miles away.