He means 70 degrees of rotation within the daily cycle, so roughly 5 hours of rotation. (He's not talking about the rotational axis orientation being off by 70

He means 70 degrees of rotation within the daily cycle, so roughly 5 hours of rotation. (He's not talking about the rotational axis orientation being off by 70 degrees.) 5 hours over thousands of years is known to be within the margin of unpredictable irregularities. Nowadays we compensate for these irregularities by altering our timekeeping by way of leap seconds.