"In the first innings I was hoping I would bring one back, but I wasn't expecting him to leave it.
"Second innings was a bit back of a length, but the same plan, just tuck him up and he chopped it on.
"It's nice when a game plan comes together."
And Dala, who has just finished a stint with Titans in the RAM SLAM Twenty20 league, hopes he has helped point the way for the South African national side.
"With the video analysis we do in cricket we felt we could expose a few of the English top order and maybe that could be good for the Proteas in the Test series," he said.
England all-rounder Chris Woakes, who took his first wicket of the trip as the South Africa XI were dismissed for 188 in reply to the tourists' 470 for seven, has no such concerns over Hales.
"He probably hasn't had the time in the middle he'd like, but we're only two days into the tour and there's plenty of time to get into nick," he said.
"He's a great player and he deserves his opportunity.
"Fingers crossed in the next week or two before the first Test he can get some more time out there and show what he can do."
With Steven Finn's fitness not yet clear, Woakes appears to be in a shootout with uncapped left-armer Mark Footitt for the third seamer's role.
Footitt took two wickets but was expensive, with Woakes playing a steadier hand worth one for 35 in 10 overs.
"I felt like it came out pretty well for me," he said.
"I was in good rhythm and my pace was up.
"You'd expect Stokesy, Broady and Jimmy to be in the starting XI so there is a space up for grabs.
"Competition for places is big and it's only healthy for the team.
"Fingers crossed I can put in some performances and get my name in that first team."
