Eye witness testimony is crap too. Even if you could answer pointed questions about your whereabouts in any given evening using Google maps, human recollection of events and their details is not great.
There are questions I am capable of answering with the police but I must accept that most questions I answer could be wrong, or another witness could be wrong and now the police can use my evidence to accuse me off being a liar... Which happens to innocent people in the US because our prison system isn't about Justice, it's about maximizing the slave count in the private prison system.
Does that take into account all the private contractors who sell services to "not for profit" prison systems and the sale of prison labor by those same prisons?
>Can there really be consequences for contradicting the other witness, without other indications pointing to who's right?
Yes. The end-goal is to infer that the suspect is being deceptive and/or lying and that, in turn, would make any statements that give the suspect any "good light" weighted less credible to their own defence.
"You said you didn't shoot the suspect but you also said you wore an off-blue shirt. 'X' said the shirt they say you in was solid blue. Why would you lie about the colour of your shirt!? And, since you're lying about that, how do we know you're not lying about shooting the victim?"
There are questions I am capable of answering with the police but I must accept that most questions I answer could be wrong, or another witness could be wrong and now the police can use my evidence to accuse me off being a liar... Which happens to innocent people in the US because our prison system isn't about Justice, it's about maximizing the slave count in the private prison system.