Explain Binary Classification with output 0.5 (True)
It sounds like your model is saying there is a 50% chance that this data point could be in either class. Since this is a special case, prediction algorithms need to pick which class to choose when there is an equal probability for each class. In this case, it looks like your model defaults to the True class.

There are some models in sklearn like random forest and SVM that have predict_proba functions. You might find more information if you look there or check if the model you are using has documentation on how its probabilities are calculated.