As usual, there are a lot of variables here.... if the client were using a .375 or was maybe a less than an excellent shot, I'd probably try to wait until the animal turns...... if he were using something a little bigger I'd make a decision based on factors such as whether the animal had it's head up or down and whether we had time to wait or not.

If the head was up and the Buff watching us (this happens quite often) I'd prefer the client to go for a frontal chest shot.....FWIW, I've never had a Buff charge immediatly after taking the bullet from this position....... they usually either go down or more often furn and run. Note that the dewlap on a Buff has a massive mattressing sffect and the larger the calibre the better for this shot......

If the animal were feeding with his head down, I'd either wait or depending on the clients self control and shooting ability etc, I'd suggest he either take the spine shot or wait for a better opportunity.

Other factors also come in on a shot like this..... such as is it the first or last day of the hunt, is it the biggest Buff I've ever seen and a few more besides

etc etc......

If it's a charge situation, I tend to shoot them somewhere in the face....exactly where will depend on the exact position of the animal in relation to me.......

Opinions are best based on previous practical experiences and my previous practical experiences have taught me that it's highly unusual for a Buff that's just taken the first shot to charge. Assuming they don't die there and then, they'll usually turn and run a few hundred yards (at least) and then look for some thick cover to hide up in....... that's when they either lie down, bleed out and die or build up a lot of angry resentment that they take out on the whoever crosses their path next...... usually the hunting party.

I'm not suggesting they won't ever charge immediatly after taking the first shot, just that from my personal experiences it's not very likely.....