Saito was never wearing the uniform hat, it was just the light from the explosion and shading of the drawing.
When Shishio fires the Armstrong cannon at Saito, Kenshin, and Sano, notice that in the still shot of Kenshin and Saito dodging the blast, the uniform hat of Saito's police officer attire appears (it is not present before or after this shot).
Shishio: I'll give credit where it's due, since they managed to find us. (peers through spyglass, panning to Saito) Hajime Saito. (moves spyglass to Kenshin) Himura, the Battousai. (moves spyglass to Sanosuke) Hmm, and someone I don't know.
Houji: If I'm not mistaken, he's just a thug. I believe he's a man of fairly notorious reputation in Tokyo, but he's insignificant compared to the other two.
Shishio: In other words, he's just another nobody.
(Sanosuke sneezes loudly.)
Sanosuke: Huh, the excitement must be getting to me.
Kaoru: You're leaving early tomorrow and you're staying up late, is that all right?
Kenshin: I did get some sleep. About half an hour.
Kaoru: A half hour, is that enough?
Kenshin: What about you, Miss Kaoru?
Kaoru: I was just going to the bathroom, and--(realizes what she's saying and slaps Kenshin on the head) Don't make me say it!
Misao: (while holding her head) To think that I allowed someone to sneak up behind me!
Kaoru: (you can still hear Misao in the background again) It's alright because she's fine, but she really was in danger.
Misao: (in the background) I'm an idiot, idiot, idiot, idiot, idiot!
Misao: It's...embarrassing! (turns to her side and starts pounding on the floor repeatedly) Embarrassed, mortified, full of spite, spite, spite, spite, spite, spite! Oh no, damn it, damn it, damn it! Spite, spite, spite, spite, spite!
Kaoru: (you can still hear Misao in the background)She's been like this for an entire day now.
(After Sano gets pissed off at what Kenshin said and punches him into a wall)
Sanosuke:(with red eyes and sharp teeth) Why do I have to be friendly with that merciless bastard? I'll settle the score with him after we defeat Shishio's group! If you understand, hurry up and show me to the Aoiya! Now that I'm pissed, I'm hungry.
Kenshin:(With a bump on his head) Yeah, yeah...
(After using the bombs Katsu gave him)
Sanosuke: I can't believe that idiot Katsu made me hang on to something so dangerous! How could those have been for self-defense?
(smirks while hanging onto a piece of driftwood in the sea)
Hmm, but I've gotta admit, that was a pretty nice parting gift. Just wait a little longer, Makoto Shishio. You and me are gonna be face to face soon enough.
Saitoh: (About Sano) But being a reliable person doesn't change the fact that he's still a moron.
Kenshin: The final attack, the Amamkakeru Ryuu no Hirameki, is a dangerous attack that it is. If I lose myself in the heat of battle like when i fought Saito and Chou, I might revert to my old manslayer self. However, if I hold back, I may not have the speed necessary to execute the final attack. I have to be able to see through the paper thin margins between life and death. If I can do that, that's when Amakakeru Ryuu no Hirameki is complete. It depends on the state of my heart at the time.
Okina, who became un-consciousness after his fight with Aoshi in a previous episode, regains his consciousness.
The full title of this episode that appears on the screen is Purgatory Bursts into Flames: The Destiny of Makoto Shishio.