I understand that some have taken to downloading the 577 to a lighter recoil level, which might explain reduced penetration or effectiveness. Tried to find a thread about that elsewhere but can't dig it out this morning. I did not read the article you mention so it may not be the case there at all.

In any event, there are no guarantees, and I would hesitate to make a generalization from one incident.

Edit: Found the thread on another board that I recalled. If you are talking about the September 2008 Guns and Ammo I understand secondhand that it described the loads as "a 650 gr solid at less than 1900 fps and another at 1950 fps." I believe the heavy 577 loads are more substantial as Taylor used 750 grain bullet at 2050 fps (again second hand).

That may explain some of the problem here.