Honestly, it could be worse. Yes, a zealous prosecutor could lay a charge of cowardice in the face of the enemy, for running in the night battle - but Abramo is not convinced he would convict. It is not as though Woljif was ordered by a superior officer to attack, and refused to do so; or ordered to hold a position, and ran from it. No, he was cut off from the chain of command, made his own tactical decisions as the man on the spot, and (all right, this is a little charitable) arrived at "break contact to reestablish situational awareness and gather force for a counterattack". It need not be the ideal, staff-college answer, to be a perfectly reasonable response to the situation as he found it; and - man on the spot. One ought not to second-guess one's subordinates, when not in direct tactical command of them.
As for being captured by the enemy, why, half the army is guilty of that; if that were a crime, he'd have to put Galfrey in the dock, and Irabeth next to her. It's true that many of the others managed to escape in fairly short order, but although it is a duty to attempt escape, one cannot well require people to win. And in any case Woljif appears to have quite successfully infiltrated the enemy organisation and neutralised them for some time. If the demons hang him for a saboteur and spy that will be well within their rights, but Abramo's not going to do their work for them! And he's brought back valuable intelligence, too. Abramo's not proposing to give the man a medal, but - well, in all honesty, men have been mentioned in dispatches for rather less fraught infiltrations.
He does take a moment to consider the looks of the thing; he's aware that he's not entirely immune to Woljif's roguish charm, and needs to be careful not to show favoritism. But really - if Woljif has spent some time undercover, infiltrating enemy cultists, that seems perfectly reasonable? Nobody will think twice about the tiefling rogue doing such work while the Hellknight and the paladin fight in the front line, or think that Woljif's neck wasn't at risk. It's not even necessary to give the impression that Woljif had been ordered to infiltrate anyone; "captured in the night ambush" and "escaped by his own talents" are perfectly true statements.