The opposite of exaggeration?

What is the opposite of exaggeration? I ask because Jenny and I had a discussion yesterday about the following events that recently unfolded:

Trinh had an accident in Jenny's car.

Winnii (who picked Trinh up) described the incident as, 'OH MY GOD! The car is a wreck!'

Phuc (who also saw the car) described the incident as, 'Whoa.. That car is a write-off…'

Trinh described the incident as, 'Oh, there's just a few scratches on it..'

I haven't seen the damage, but, Jenny and I both agreed that Winnii exaggerates, so her description can be toned down two notches, meaning the car is badly damaged, not a total wreck. We also agreed that Trinh plays things down (the opposite of exaggeration), so we can bump up her description up two notches, meaning the car is damaged more than just a few scratches. So, in conclusion, the actual damage on the car is a cross between those two descriptions, meaning the car must be considerably damaged. I believed Phuc, whom I don't really know well at all, but her description sounds more accurate than the other two.

Jenny described a conversation between herself and Trinh, which clarifies the situation a little more:

Jenny: How damaged is it?
Trinh: There's just a few scratches on it..
Jenny: Can you close the bonnet, or is it hard to close?
Trinh: No, you can't close the bonnet..
Jenny: Was there any leakage? Was the car leaking?
Trinh: Yes..
Jenny: What colour was the fluid?
Trinh: Green
Jenny: That was the radiator you hit then..

It's been confirmed the car is a write-off. At least Trinh is ok, just a bit of soreness when the car had the impact.

So peoples. What is the antonym of exaggeration?