Band Adjustment Question.

[69fast]

I have a built C4 transmission (closer to an FMX now) that recently started slipping from 1st to 2nd, not shifting out of the passing gear and just acting strange all together. After further investigation I found that the band adjustment bolt had worked its way loose (about two inches between trans and locking nut). I snugged it down then backed it off 1 1/2 turns and tightened the locking nut, it now seems back to perfect. My questions are if this has happened to anyone else and how crucial is it to have the perfect tightness? I feel pretty confident I did it right but didn't know if it would be worth it to have a shop double check it? Thanks in advance for any help.