I’m not saying just an explosion, I am saying afterward. The fight with the Queen, Predator, and Lex.
All of that can be captured in good detail with a satellite.
Today we can get such good intelligence from satellites that we can pick out individual faces.
Weyland industries could be ahead in that area of technology, and managed to a get a decent look at the Queen, the Predator, and even the Pred ship at the end.
All of which they would be very interested in.
Now as far as Ash wanting to exaggerate company policy in order to get the expedition down there, perhaps.
We have no idea what laws are like in that time and place, and they were originally told, by ash I am presuming, that is was a distress signal, not a warning.
It was only when it was too late that Ripley discovered it to have been a warning.