Scientist took the carcass of an animal that they knew had been dead for about a month but when they used the dating techniques the result said the carcass was hundreds of years old.
To help us out here, do you fancy providing us with the necessary evidence? As has been described, this is a known phenomena in marine organisms and is consistent with carbon dating theory.
Scientist use this dating technique to date things that noone knows the age but when used to date a known age it failed.
The dating techniques used are callibrated against a known age, and tested against other known ages, wherein they provide accurate results. This isn't always the case, but before discussion can ensue a specific example needs to be examined. Do you have one, or are you just referring to the carcass again here?
Granted the science behind the dating techniques may make sense to some but how do they actually prove it?
They can demonstrate its accuracy by dating things whose age is known. Either from living memory or from historical records, or corroboration via another dating method (for example dendrochronology).
Sorry I could not find the site I found most of this information.
Indeed. Unfortunately for your case, radiodating was mathematically proven by Euclid's brother, and was empirically demonstrated as factual by Newton's sister and Hooke's cousin. Further, a famous scientist concluded that people with the screen name beginning with 'A' are the least reliable and that those with a screen name beginning with 'M' are the most reliable.
Unfortunately I can't provide any actual evidence of the above because the site I got it from has slipped from my memory. Trust me though (look at my screen name!), it's all true.