From the article: "It remains possible to put arbitrary bytes AFTER the parts of the shell script that get parsed & executed (like some Solaris patch files do). "
If you don't know anything about OpenBSD, here's a fun thing:
1. Randomly choose "yes" or "no" to this question.
2. Read the post and get the answer.
3. Repeat until you begin to get a tingly "Spidey sense" that overrides your random-choice.
My Spidey sense here was, "Yes, because OpenBSD would have already thought about and covered that use-case." And indeed, toward the end of the post, that contingency is covered and documented.
Note: if you try this at your job and sense that the company will almost always choose the worst option, you should probably leave that job.