In "An Occurrence at Owl Creek Bridge," Farquhar is depicted, at the time of his hanging, as anxious and terrified by the prospect of his execution and perhaps also regretful for his own earlier decision to attempt to destroy the bridge.
This sense of anxiety is already, at the very least, implied in the story's first chapter, as Bierce describes Farquhar's own train of thought in the moments before his death, with his attention drawn towards "his unsteadfast footing" and "the swirling water of the stream racing madly beneath his feet" (ominous imagery on Bierce's part). While trying to dedicate his last thoughts to his family, he is driven to various distractions and tormented by the sound of his own ticking watch. The combined effect of these details suggests the impression of someone ill at ease.
At the same time, there are also the details contained in his imagined escape. Note, first of all, just how terrifying this vision actually is, as Farquhar must first escape the noose strangling him (even while being submerged underwater for that matter), before next overcoming potential death by firing squad. This entire scene is shaped by a sense of desperation as he must struggle against overwhelming odds.
Finally, there is the very end of his vision, where he sees himself reunited with his wife. Here particularly, there seems to be a possibility of very real regret on his part: after all, he was the one that left home in order to destroy the bridge in the first place, driven by his enthusiasm for the secessionist cause and military life. In that sense, it is noteworthy that, at the very end, his mind is now focused on the life he left behind.