Given the nature of the tanker's cargo and employment - it's shifting jet fuel for the US government - there's been a fair bit of speculation that something untoward happened here.
It's unlikely - Solong was passing exactly along its previous track through the area and was likely on autopilot to a regular waypoint. If it wanted to ensure a collision it wouldn't necessarily line it up nine hours in advance either. There's nothing suspicious in this - just incredibly stupid.