Strange battle ... why this?

[NullAshton]

I think the reason why it stayed around and waited to get killed is because of the default strategies. It couldn't complete it's primary strategy, so it went to the secondary strategy which was probally point blank. Not sure, but having the secondary strategy be "don't get hurt" might work well with missile ships.

[Beorne]

Yes. Probably this is the reason, the secondary default is point blank.