I think if we asked Terry Grammer, Julian Hanna or Van Rensburg...

I think if we asked Terry Grammer, Julian Hanna or Van Rensburg we'd get a pretty dirty look and a curt response along the lines of "how many holes have you jokers drilled?"

If you think about it, with a 20 degree deviation over 533 m you're talking fractions of a degree per metre - an average 3.75 degrees over 100m. The deeper you drill the more a slight deviation will be magnified. My experience with drilling is zero ( as I'm sure it is for most here), but deviation is the nature of the beast as far as I can tell. There is certainly nothing to suggest someone stuffed up.

This website offers a good explanation of the effect of deviation: http://www.pajari.com/information/why-bore-holes-deviate.html

Sounds like they wouldn't have known deviation was occurring until they surveyed the hole afterward, so at 400m depth saying they were nearing the target was probably exactly what they thought. Bit too easy to be armchair critics here I think. The hole no doubt gave them some useful info - they will know how that 48m of weakly disseminated compares to background in the area. I assume the downhole survey they have been doing on each hole will also have given them a lot of useful information.