Bay United pulled a goal back, 2-1, in the 85th minute from substitute English import midfielder Sam De St Croix, the latest signing from the Hamilton Wanderers during the new year transfer window.
But it was too little, too late for the visitors, who threw the kitchen sink at the hosts in trying to find the equaliser.
The first Wellington goal, which Robertson and his sidekicks responsible for putting up the shutters inexplicably didn't go up for in the cornerkick, was a soft one and Angell agreed.
"It's very, very frustrating. They score from a corner and that's frustrating because it's a free header," he said, chastising the Beefeaters for not even going up with Kayara.
"It's the responsibility of every individual to do their jobs that they are given to make sure that sort of thing doesn't happen but, unfortunately, it happened to us when we were attacking against a team who are at the top of league. It's frustrating that we haven't come away with anything."
Angell bemoaned referee Nick Waldron's decision to wave on play in the 49th minute when Kayara came under some scrutiny for allegedly bringing down Bay United Canadian import striker Gavin Hoy about 5m in front of the left upright.
"Look, situations change the complexion of the game because I think we should have had a penalty but the referee didn't see that," Angell said, adding he had discussed the matter with the official after the game but still came away none the wiser.
In the coach's opinion, Kayara was on the wrong side of Hoy in full cry of the ball which made the former culpable.
"He [referee] said there wasn't enough contact - whatever that starts to mean, I don't know."
Nevertheless, Angell said yesterday's performance typified their so-so season - oodles of chances, loads of endeavour but not enough killer instincts to put the ball where it mattered.
It rankled with him that his players had the propensity to switch off at the most inconvenient times to allow for the momentum swing to run across into the oppositions' corner.
To make his point, he dwelled on how the lack of focus defensively had undone them again.
"I can't quite put my finger on it but it's something that whoever gets into positions to score can't quite convert it as clinically as what we'd like.
"We never seem to get out of reach of teams in relation to what we're doing and how we're doing it."
For Angell it all goes back to paying attention to the finer details.
He reflected on Wellington's second goal, bereft of ideas on how that ball could travel 50m across the pitch without any challenges.
"We should have had somebody be able to eventually cut that ball out but, again, probably not just one but two players were not quite there to stop the ball getting into the box.
"Suddenly we're 2-nil down and we have a bigger mountain to climb but one I didn't see us having to climb after the first half."
Angell said injury to import Samuel Adjei in the 11th minute didn't help their cause after the Ghanaian/American striker had started brightly.
"The way we play he gives us different dynamics ... BJ [substitute Bjorn Christensen] is not quite the same player but it is what it is and the squad is what it is."
The Bay host a rampant Eastern Suburbs at Memorial Park, Palmerston North, this Sunday and Angell rated them as difficult as Wellington.
"If we put those facets of games together we can beat anyone in the league," he said, adding poor decisions on both ends of the park were deterrents to achieving that state of nirvana.
Bay rightback Hayden McHenery again had a robust game and almost demands presence in the engine room with his surging and probing runs to put his side on the front foot.
In other games, Suburbs beat Hamilton Wanderers 5-3 Tasman United eclipsed Southern United 4-2, Auckland City edged out Canterbury United 2-0 and Wellington Phoenix Reserves pipped Waitakere United 3-2.
