It's also possible an Apple employee did the donation.

In most enterprise places I've worked at (as a software engineer), we've had a small discretionary budget we could allocate every year (or 3/6 months) to donate to OSS we've relied on. This would usually be a small budget, per team (last time it was £100 a year), and sometimes it had to be allocated based on how big a part it plays in my specific team's work.

So I see it as quite plausible that a team got a budget for such donations, and since BSD made up part of the work, they had part of that budget allocated and donated.

Unfortunately with big corps it's hard to properly align between teams when it comes to bureaucratic BS, so it's even possible that Apple donated under dozens of names because yay, red tape if you want to do it the right way.