I think you can say this is a dodgy call overall but if you compere it to
1-chris fergusons call versus t.j coultier a9o v aq
2-johnny chan call a7o versus helmuths 99
3-johnny chan call a9o versus frank henderson 44
4-t.j.coultier a3o call versus bill smith 33
all final hands in the wsop it can maybe seen slighly differently
Now i don't know how these hand were played out, and how the betting went etc.
Ax plays alot better calling an all heads up than 3's does, as ax is ahead of alot of the range they are calling, for example it plays better against all of the following hands, kq,kj,k10,k9,qj,q10,kk-44.Also the top 3 might even get lucky and be dominating a smaller ace.