"squid"

I don't get it why people keep assuming that this was a organic lifeform.
All the evidence suggested it was not.
1) light
no organisms on earth use light to navigate. I.e. whales and dolphins use sonar. bats echolocate etc. there is not one animal shining light in front of itself. light is only used by animals to confuse others or to attract mates. it is very inefficient way to navigate

2) the "creature"'s presence was always coupled with increased radiation readings. in other words it probably used a radio active power source.

These 2 pieces should have been enough for anybody to make the determination this was an artificial creature (independent robot or remote controlled drone).