Not sure if it is a bug, I got Active Sensor Strength 36 from an ally, while I was still at 21, skipping 28. I can still research 28 as well as 48, but there is of course no point in that, so I think I should get the skipped tech as well.
On the same note as DuraniumCowboy, getting tech from other sources does not remove them from the queue, the projects still started.