Your question is kind of irrelevant,the MOT tester will not be bothered what was or wasn`t wrong last MOT,the current one is what counts and it is his/her name against it, as for wear/fault on one tyre it may be a side wall cut/tread damage,and does not matter whether one side is worn before another,could be down to driving habits/lack of maintenance but what is certain if they are not repaired then no MOT.
cdc, May 2014