  We report a precise determination of the 19Ne half-life to be $T_{1/2} =
17.262 \pm 0.007$ s. This result disagrees with the most recent precision
measurements and is important for placing bounds on predicted right-handed
interactions that are absent in the current Standard Model. We are able to
identify and disentangle two competing systematic effects that influence the
accuracy of such measurements. Our findings prompt a reassessment of results
from previous high-precision lifetime measurements that used similar equipment
and methods.
