I used to use bone meal and the same thing would happen to me. Skipped the bone meal this year and no digging yet.I dont know where you live or what is in your soil but in Hawaii wild boars will sometimes poke their snouts inside your pot looking for shit, this is one reason I dont use bloodmeal, fish emulsion, or other type amendments in my soil.
I have yet to have a boar completely uproot a plant but every time this has happened before it has been when they were in very large pots.
my plants far outgrow the small bit of fencing around the base of them, and my plants are safe from critters and choppersits hard to keep the animals away. better to lose half your plants to animals than risk getting caught by aerial seeing your fences though... just my opinion.
i had some digging my plants up too.. they just threw the plants to the side and dug in my container.. looked like they were looking for bugs to me... probably raccoon or possum.
For some reason animals love to dig into a fresh turned hole, ive found that it helps alot to go out and turn my holes a few weeks in advance this gives them time to satisfy their curiosity in my dirt. I quit using wire couple years ago mainly because i felt it helped make my holes more noticeable from above. theirs alot of good products out there for repelling animals. My favorite is liquid fence.