Well something is proven right for the level of knowledge supported by observations about what it's trying to demonstrate. Then better observations/testing can prove it wrong, or off and not 100% accurate, but generally accurate, etc. Proving something wrong can even turn out to be wrong since it's also based on testing and observation. Strong evidence leads to a generalized conclusions of proof about something, but yes semantically it's often not "100% proof" since ya never know what else can be demonstrated/detected/measured at some later date.