Agreed it's very short. However, it causes a problem in the full version of the circuit. I'm using two LT1158's to form a full bridge for a DC motor controller. The extra little current that gets pulled into the motor, along with the shoot-through current, causes the over-current protection to kick in and shutdown the device.
Based on the voltages present on the gate drivers, it doesn't seem like the shoot-through should be happening at all. For example, when the high side turns on, the voltage on the low side gate driver is about 1V. Yet an 8A spike of shoot-through current is shown. Wouldn't the Rds of the bottom FET at a Vgs of 1V be way too high to allow 8A of current?