Type 2 to Normal

Hi everyone... after i was diagnosed with pre diabetes i was scared and that result in much searching thru internet , libraries and some interviewed friends who has family history of diabetes... now, can you help me explained some cases if type 2 is reversible? i now most of the site and some books told pre-diabetes is reversible some told that type 2 is irreversible... So i have 3 cases that i want to share and i am so confused so please help me.

First, my father in law got stroke 5 years ago, when in the hospital we are told that aside from hypertension he also has diabetes type 2. But the family was more thinking of his hypertension because that time was too high. So no diabetics meds was given. He was told to come back after 1 month for executive check up. His left body got paralyzed. After a month, executive check up was done. Sugar was in the normal range FBS is 89. Then was ask to came back every 3 months but until now his FBS is in the normal range.

Second, my friends father was diagnose with type 2 diabetes after being confine for liver cirrhosis, at first he was taking meds 3x a day. but after a years of slow recovering his doctor told him his not diabetic because without meds he's FBS is also in the normal range.. until now i ask him if he still taking meds and he answered no, my sugar only went up because of complications in my liver but i am not diabetic.

So, how come they went to normal if they are type 2? Is it because they are not true diabetic and there blood sugar only went up because of complication?