Visible crew/equipment: When the guys walk from the deli, talking about which girl they are taking to the prom, you see a reflection in the cars parked along the side, of a crew member walking with a boom mic.
Factual error: At a scene where Ron is in the Veteran's hospital doing physical therapy, it is supposed to be 1968, but the song playing is "American Pie." The song didn't come out until 1971.
Other mistake: During the big protest march scene which is supposed to have taken place in the early '70's, one Vietnam vet who is sitting in a wheelchair is clearly wearing a pair of high top Reebok sneakers introduced in the late '80's.
Continuity mistake: When Tom Cruise is lying in his hospital bed and begins freaking out, he knocks over a pitcher from the small table next to him. In the next shot the pitcher is back on top of the table. (00:57:00)
Factual error: During the closing credits, two songs appear misspelled: "Hace un ano": The correct spelling is "Hace un año" - okay, not all keyboards have the Spanish "ñ" - , and Meleguena. This one is waaaay wrong: The correct spelling is Malagueña.
Factual error: In the late sixties, when Ron is in the Brooklyn Veterans Hospital, the radio plays "American Pie." This wasn't recorded until 1971.
Factual error: Kovic is in the Marines. "Choppers" are called "Helos" in the Marines, and a "Medic" is called "Corpsman". Kovic uses the Army terms.
Factual error: In the opening scene when the kids are playing "War" in the woods, Ron Kovic as a child is carrying a replica of a Beretta M9 handgun. However, Beretta M9's weren't even designed until the 1980s.
Continuity mistake: After Kovic is walking with his crutches, falls and his bone breaks, the crutches keep changing positions between shots.
Answer: He doesn't see anything. He hears his blood dripping back into the makeshift machine the doctors have set up and realizes it isn't working properly. In the previous scene he was told that if they couldn't get the machine to work, he would never walk again.
No, in the previous scene he was told that if they couldn't get the machine to work, he would lose his leg. He was already told he would never walk again.