I noticed 2 strange things with the Gargantua at the end of Surface Tension.
Firstly, it totally ignores the 2 human grunts, that are shooting it, when you fall out of the vent. That is totally weird, considering you aren’t the one shooting at it, yet it goes for you first. I then tried noclip and was surprised, that it was not even attacking them, when you aren’t around. Maybe they could just die automatically, when it breaks through the door (debris etc.).
Secondly the Gargantua is even shaking the Mortar observation post, when you aren’t standing on it (for example, if you have jumped in the water).