But an e-ticket should not have a segment limitation other than the number of segments that the airline is able to price. The airlines are able to price more than 16 (and 20) segments, so they should be able to e-ticket them as well. Sounds like an excuse to me.

The 20 segment limitation is, imo, easily the worst change that Oneworld has made in the rules in the past four years. I can see it now, "in order to conserve the number of bytes required to book the ticket, we are limiting the number of flights to three...unless you are going from/through/via Ghana or Nigeria where you get five."