DRV8424: DRV8424RGE BOUT1 (No.6) pin soldering is melted.

Tool/software:

Hello guys,

One of my customers faces DRV8424RGE trouble.

The trouble is that the solder on the BOUT1 pin (No.6) is melted sometimes when a specific motor is connected to DRV8424.
But DRV8424 is not broken. DRV8424 is work well after re-soldering between BOUT1 pin and PCB pattern

At this moment, they have the following questions.
Could you please give me your reply?

Q1.
Have you ever seen or heard the phenomenon?

Q2.
They checked the BOUT1 pin voltage when DRV8424 is driving the motor.
Then they found that BOUT1 voltage was less than -1V or more than VM+1V during 400~500ns.
Is there any possibility BOUT1 pin solder melting in case of the situation above? 

Best regards,
Kazuya.