Did this killer's behavior warrant the in game report?

As the others have already said, this is clearly a style of play the Bubba is known for employing. Camping is a strategy that the DEV have validated time and time again. If you look at various Killer Perks you will see there are even Builds clearly intended to encourage it. Let me make a polite suggestion, purge the word "toxic" from your vocabulary. It is a meaningless word. It means whatever anyone WANTS it to mean. The only things you should be reporting people for is Hacks, excessive salty behavior, the many idiotic "isms," i.e. racism, sexism, etc., Exploiting bugs, and rage quits and disconnects that screw up the game. In fact, the reporting system kind of gives you a guide to what you should be reporting when you are in it.

Camping, tunneling, slugging, and the Mori are NOT something you should be reporting. I find people clicking their flashlights excessively and tea-bagging annoying, but I'm not reporting that either. Most of the time they have a tactical reason for doing it, i.e. they want me to chase them so their buddies can get something done. So forget about trying to interpret "toxic" behavior, and only report specific actions which clearly violate the game's rules. For example, I think people who post endless screeds and complaints here in the Forum or report people for normal game play are toxic. See how subjective it is? You are now toxic. Get my point?

I should, ethically, be crystal clear about my own bias and conflict of interest here. I like to play Spooky Myers Builds (also known as Jump Scare Myers). That means I'm SLOW but I can wall hack. I love the basement because it offsets my greatest weakness while playing into my greatest strength. I can camp the Basement without even being in it, the building, or that close. I can appear to leave and watch people head for the rescue. I can usually time my entrance to make a successful grab and put the would be rescuer on their own hook.

If I get two people on the hooks in the basement at the same time, the game is usually over. The others either come try to rescue too and get nailed, or they realize the situation and try to do Generators but with their reduced numbers (and by the time they make the choice to write their pals off) I can safely leave the Basement and keep the pressure I need up without too much trouble. All that being said, it is possible to get people out of the Basement from me and from those crazy Bubba builds too. It isn't easy but it is doable. It requires coordination and timing. And if it were easy, there wouldn't be much point to the game.

My helpful tip is to stay away from the darn basement. Survivors seem to have a strange obsession with running toward its vicinity in chases, wanting to poke around down there early when they assume the Killer isn't watching to check out the chests, and for some reason fixate on any Generator nearest to the Basement. And if there is a Totem spawned near it, Christmas has come early. They will come back again and again. Like I said, I only need two on hooks in there at the same time and the game is usually over. So, as a Survivor it behooves you to figure out where the Basement is and take that into account when you choose your Generators as well as the direction you are running. Most Basement Dweller Builds can be severely curtailed simply by avoiding that area of the map.