Titans error that proves he's not quite on Batman's level just yet. Dick Grayson's career with the Titans has been littered with low points - Aqualad's death, cruelly manipulating Jericho, narrowly avoiding defeat against Trigon... Since making the transition to Nightwing, however, Dick has become a far more assured leader. Things haven't always gone his way, but Dick's judgement has been sound as he balances heart and mind to make the best decisions for his team.
And he's going to need those sharp instincts if Titans season 3's Batman hints pay off. Since Bruce Wayne left Gotham earlier in the season, Nightwing has become the city's de facto Batman. He liaises with Commission Gordon, has his own signal in the sky, and makes full use of the facilities at Wayne Manor. Titans is even teasing Dick Grayson taking over the Batman mantle permanently in the near future, with Bruce himself seemingly finished fighting crime. Titans' new Batman plans might need to be put on ice (that's not a Mr. Freeze pun, we promise), as Nightwing just made a very un-Batman-like mistake.
Nightwing is totally aware of Scarecrow's goal - destroy public confidence in the Titans and replace them with his own superhero creation, Red Hood. To this end, Jonathan Crane spreads anti-Titan propaganda claiming the group are violent vigilantes not to be trusted. He frames the superheroes for poisoning Gotham's water, and offers a $50,000 reward for their capture - and it's at this point Nightwing really messes up. Naively, Dick Grayson believes he has a perfect solution to the Titans' predicament. He suggests the group hand themselves over to the GD, post bail using Bruce Wayne's bottomless bank , and then slip quietly into the shadows to resume their superhero activities in secret. This foolishly optimistic plan is not Nightwing's finest moment.
Scarecrow is, true to type, several steps ahead of the heroes. Jonathan Crane (via Red Hood) already paid off a high-ranking police officer to ensure that when Nightwing and his crew tried marching into GD HQ peacefully, a brawl breaks out, tearing divisions into both the Titans and the cops. Scarecrow played Dick Grayson like an especially moody fiddle, and now the heroes are scattered and hated, the police are shooting each other, and Commissioner Gordon is now Inmate Gordon. Everything is coming up Scarecrow in Titans season 3.
The bigger problem is how Nightwing should have known this would happen. Since the very beginning of Titans season 3, Scarecrow has been playing an intricate game of psychological chess - Red Hood's bird-themed crimes, the elaborate murder of Hawk, tricking Starfire into releasing the poison, etc. By now, Dick Grayson should expect Scarecrow to have a plan behind the plan. Nightwing should've also anticipated Scarecrow would predict and for the Titans handing themselves in. Jonathan Crane is deeply familiar with the U.S. justice system, knows Dick has access to Wayne money, and is aware of the personal connection between Nightwing and Gotham's Commissioner. It doesn't take a genius criminal psychologist (though that's exactly what Crane is) to figure out Dick Grayson's first move would be handing his team to the cops.
It's hard to imagine Batman making this same rookie mistake. Despite his reputation as a master detective, Bruce has made plenty of goofs throughout his time as DC's Caped Crusader, and many a villain can claim to have duped him at least once. One of Batman's greatest strengths, however, is avoiding the predictable play. As well as guessing how his enemies will act, Bruce Wayne is a master at predicting how his enemies think he will act. Dick Grayson does neither with Scarecrow in Titans season 3, proving he isn't quite up to replacing his mentor just yet.