Paddy Butler crashed over for a last minute try to condemned the Blues to the fifth defeat of the PRO12 campaign.
The Blues came back from behind to earn a 24-21 lead in the closing stages thanks to a debut try from Lucas Gonzalez-Amorosino and a barnstorming score for Manoa Vosawai.
But Hammett was left scratching his head after the Blues extended their winless run to six games.
He said: “It was a pretty quiet changing shed, as you can imagine. From a coaching perspective, if I take the result out and look solely at the actions and the game, that’s the best we’ve played.
“We played well for long periods. Our structure was good, our intensity was good, our ball-carrying was generally very good. What let us down occasionally was individual skill-sets, some passing, some missed kicks to touch and turning pressure into points.
“Penalties cost a lot as well. If you look at the reason we lost, ultimately it would be discipline in the first half. But from a collective point of view, it was hard to ask more from the group.
“Anyone who walked away from there is scratching their head why we didn’t win, myself included. I imagine Munster will be buying a Lotto ticket tonight!”
But Hammett took positives from the individual performance of Argentina wing Gonzalez, who crossed for a try after Rhys Patchell spotted space down the blindside.
He said: “He was extremely solid. He caught every high ball, he didn’t turn anything over, scored a very nice try, his kicking game was good and he was generally pretty accurate on defence.
“I would imagine the crowd will go away and say that’s not too bad. His challenge now is to back that performance up.”
