"You've probably put that quite succinctly," Hesson quipped. "It's something we need to firm up on. With the DRS, you do need to take time to gather information. We missed out on one against Pakistan earlier in the summer when we took half a second too long, and there's probably a couple in this series where we let emotion take over and made instant decisions which weren't right."
Hesson defended the work of his rejigged slip cordon in the absence of the injured Ross Taylor.
"Tom dropped one at first slip, but unless B-J grows another four inches he's never going to catch the one which hit the end of his fingers.
"To consider there's a whole heap [of dropped catches] is off the mark. Tom's fielded at first slip in ODI and test cricket quite a lot, and been good.
"In some ways he had too long to think about [the spill]. You want those to arrive quickly, so you're more instinctive."
The Wellington forecast is for rain leading up to the test start on Thursday, but fine for most of the match. The pitch is expected to be under covers for much of the build-up.
Hesson was asked whether that meant a return to an attack of three specialist pace bowlers and one spinner.
"Some of the ODI wickets were under cover for a long time this summer [before games] and they spun a bit more. It's a matter of rocking up, being open-minded and seeing what we're dealing with.
"You can't put a marquee around it and dry it out."
Given the onus placed on two spinners in the Dunedin test, Jeetan Patel was New Zealand's sole presence before lunch on the fourth day, bowling three overs. He bowled 36 in total during the second innings, taking two for 72. He was preferred as a means of taking the ball away from the South African left-handers.
In contrast, Mitchell Santner only bowled his first over (his sixth of the innings) at 3.37pm. He took one for 37 from 19 overs.
"They bring slightly different qualities," Hesson said of Patel and Santner. "One [Patel] is able to bowl a lot of overs, which was required on this [Dunedin] surface and he can control the run rate. They offer something different to left-handers and right-handers, and one [Santner] bats better than the other.
"It depends on the balance we want to go in with, rather than ranking them No.1 and No.2."
Taylor's right calf injury has ruled him out of the Wellington test. His replacement Neil Broom is set to make his debut.
Boult has travelled to Wellington where his sore left hip and pelvis will be monitored. Tim Southee is expected to return regardless, on a more seamer-friendly pitch. If Boult does not pass muster, Matt Henry is next in line.
