All signs point to the phenomenon being natural. David certainly doesn't have the wherewithal to cause a "stellar ignition" from his place on the surface of the nearby planet, nor could he have predicted that this particular ship was passing nearby and that they had just stopped to unfurl their energy collectors at that precise moment.
TENNESSEE: What the hell was it?
WALTER: A highly charged shockwave from a
nearby stellar ignition. As the
sails were deployed for the refuel,
we absorbed the full brunt of the
storm. If we had--
In the official novelisation, it's described as a 'cloud' of charged particles, one that just happened to be masked by a wide variety of other spacey-wacey stuff that's in the vicinity.
“Sector 106. Very close. Source was masked, hence the unusual—no, extreme proximity prior to discovery. Undetectable earlier due to unique concatenation of spatial and gravitational distortion in the vicinity. Apologies. Initial analysis was insufficient to gauge intensity, as well as proximity. Reappraisal suggests possibility the event could be substantial. Unable at this time to predict risk.”
The system and its surrounds are clogged with crap that's accumulated nearby. Again, there's no sign that this is intentional on anyone's part.
Oram was gratified to be able to interject. “View obviously is blocked
from Earth. Dense nebulae, dust cloud, periodic flares screening out
the infrared—maybe when the searcher for this sector made its pass,
this world was at perihelion, on the opposite side of its star from