As I see and hear it, changing the angle of the bow won't help.
Again, it is a bow that is too fast or too light for the lower note. Too fast and too light is actually the same, given you don't change the bow placement. How you adress it will result in a different dynamic. If you adress it with more weight, you will get a jump in volume. So slowing the bow down (perhaps with a tiny gap/stop in between the notes, as Damon Smith writes) might be a better solution.
But in general, you might try playing with more weight and a closer to the bridge (as Don Kasper wrote). Even if you are not into that kind of sound, you are certainly going to learn a lot by doing so. If you do not like to play close to the bridge, you might actually play close to the bridge and try to get warmest, least scratchy sound possible. Don't go for a penetrating, soloistic sound. Just a "normal" bass sound, but much more dense and firm than you are used to, not louder or brighter. You will immediately feel in your, when the hairs are loosing contact on certain notes. These are the notes, where you have to slow the down. Once learned, you can apply this to all kinds of other contact points.