All figures are standard so it is not possible to actually own a TT that has a longer body part
HT should have been more helpful though in clarifying this but since that is not the case maybe we can help here:
The underlying TT body consists of many parts that are snapped together using mostly clips (possibly screws as well). The longer arm is likely caused by one of the parts (hand, forearm or upper arm) not being fully inserted. You can take of the hands off (carefully) on both sides and remove the gauntlet to push up the sleeve to see the elbow joint and compare the underlying limbs and hopefully you will see which part is off.
Somebody mentioned disproportionate legs and I would say it's the same problem as it is highly unlikely that they made a few limbs at wrong length when they use molds to do so.