Firstly, where in the scripture explicitly said Abraham left haran exactly when the father died? He might have left earlier before his pagan father died at the age of 205. Chronology doesnt mean it has to be sequentially sentence for sentence. Perhaps Terah was 70 when Abraham was born, then took Abraham to Haran, then Abraham left Haran aged 75, and then Terah died in Haran aged 205.
Stephen in acts is a liar 7:4. he was not chosen by god and thats why chrisitianity lies shouldnt taint god's torah.