Continuity mistake: When Neo wakes up in the station, he is sometimes right next to the edge of the platform and sometimes further from it. (00:04:10)
Continuity mistake: At the beginning of the movie when Trinity and Morpheus first go to visit the Oracle, if you look behind them there are two wooden frames that are on the back wall where Seraph is, then a few shots later they are on the wall where Trinity and Morpheus walked in. (00:04:55 - 00:05:30)
Visible crew/equipment: In the scene where The Oracle is talking to Trinity and Morpheus, you can see the stage lights in the glasses worn by Morpheus. (00:06:40)
Continuity mistake: Sati and her family leave one suitcase when they get on the train (the one Neo was carrying), but when the train comes back and Trinity steps out, there is no suitcase. It can't have gone anywhere - as we see when Neo tries, the only way out is on the train, otherwise you're caught in a loop. (00:14:05 - 00:24:00)
Audio problem: As the trio break into the club, they take on some bouncers. One of them gets his gun turned on him by Trinity, pushed right into his chest - we hear two gunshots, with corresponding wounds, then a third shot which has no effect. (00:14:50)
Visible crew/equipment: In the Merovingian's club, when Morpheus knocks the girl back and shoots with her gun you can see the white lights/screens in his glasses. (00:16:10)
Continuity mistake: When Trinity, Morpheus and Seraph go to see the Merovingian in his club, there is a fight scene before they enter the club. When Trinity kicks the guy at the end of the fight scene, the guy has his arms by his side. In the following shot they are now outstretched. (00:17:00)
Continuity mistake: When Trinity is meeting with the Frenchman, the olive in his martini changes. In the first close-up shot, he only has one green olive on the cocktail stick. From then on he has two, until he eats one. (00:19:50)
Continuity mistake: As the three start to fight at the Merovingian's club: after Trinity snaps there is a shot of Seraph pushing someone down as the man in black pulls the gun on him. To the right, there is a guy who is hurled to the floor by Trinity. In the next shot, Trinity hurls the man again. (00:21:30)
Continuity mistake: In the scene where Neo sees the oracle at her home, as the shots go back and forth during the dialog immediately after she sits down, her cigarette pack goes from closed to slightly open several times, until she takes a cigarette, then it stays slightly open. (00:25:00)
Continuity mistake: In the scene where Neo is talking with the Oracle in her apartment, the Oracle sits down at the table, picks up a bracelet, and right before the shot changes, you can see that it is on her hand, almost to the thumb area. When we cut back to her a second later, the bracelet is back on the table, and she picks it up and puts it on again. (00:26:10)
Continuity mistake: Just after Neo has seen the Oracle he is jacked out Trinity says "How are you feeling, are you alright?", her hand is on Neo's shoulder. The following shot her hand is on his back, then back to his shoulder. (00:29:10)
Revealing mistake: When Smith goes to see the Oracle and he puts two of his fingers inside her forearm, if you pay attention, there is a circle where the green effects start, they don't start from inside. (00:33:25)
Continuity mistake: In the middle of the film when the captains and crews of both ships are discussing routes, the first shot we see Niobe. Behind her there is a guy at the side of her with a grey like t-shirt or jumper. The following shot he is standing behind her. (00:42:05)
Continuity mistake: Near the beginning when we see Neo walk into the room where the captains, Morpheus, Trinity, and the others are, if you look at Trinity she is standing behind Link in one shot, then he is standing behind her in another, and it is like this for several shots. (00:42:50)
Continuity mistake: As everyone is saying their goodbyes before entering the ships to go off to war, Neo's interface sockets on his spine keep appearing and disappearing during angle changes. (00:48:00 - 00:49:40)
Continuity mistake: In the scene where the "Smith infected" Bane has the scalpel to Trinity's neck, we first see Bane's head just right beside Trinity's lips (on the side). But in the next shot, Bane's head is way back near Trinity's neck still holding the scapel. (00:51:00)
Continuity mistake: In the scene where Bane has the scalpel to Trinity's neck, the bloody mark below it keeps disappearing and reappearing. The scalpel changes positions too as well as the blade itself changes. (00:52:55)
Continuity mistake: When Smith, in the flesh, has Trinity with a knife at her throat, one scene has a blood mark on her neck. The next scene, a moment later, shows the blood mark gone. (00:53:04)
Continuity mistake: After Neo has been blinded, his eyes and everything around them is burned and red. Right after the fight, when Trinity sees him blind for the first time, his eyes (or eyelids) are grey, and only the rest is red. (00:56:55 - 00:57:40)
Answer: They never wanted to have the possibility of it getting set off accidentally, as it would render the entire dock area (and possible more) inert instantly. In fact, they probably weren't terribly prepared for the Sentinels ever to find/reach their location. In 100 years, they hadn't yet.
Rooster of Doom