Drunk Employee Caught Company Truck On Fire

Alright so I co own a pool business in Texas 50/50 and we have two employees. Now I realize this is a bad idea but our second hire was a mutual friend my partner and someone my business partner (BP) considers a very good friend

On new years my BP and our employee got together to celebrate, I had no knowledge of this I’m not salty about that. However the next parts are going sound like I decided to work with and hire a couple of idiots

When our employee was leaving his place to go to my BP house his gf parked behind his personal vehicle and he was lazy so he took our work truck we provided him. I’m not sure how long he was at my BP house but I do know my BP had seen him drinking as or provided him alcohol. Anyways some time passes and our employee wanted to light fireworks so my BP wife’s goes and gets some and they’re lighting them off in the driveway. All said and done he leaves a short time later and the used fireworks he lit off caught on fire in the company’s trucks bed.

Luckily someone passing by pounded on his door to let him know about the fire before it got to any chemicals or totaled the truck

A couple days go by and the employee and his gf are at my house for late Christmas gift swapping this is when I found out about him being rather intoxicated. We of course were talking about the situation and my wife asked him if he was drunk and he said “I was highly inebriated” I’m starting to wonder how this man that I thought personally highly of made such bad choices.

As I’m wondering how this happened my wife started letting her thoughts on the matter be heard. He started talking back about how this “was an accident” that he was “just trying to help clean up” anyways he got very flustered and left. I was completely overwhelmed by the situation feeling of betrayal and I just lost a friend and an employee.

What’s really getting to me is the employee has not even apologized and until the gift swapping event he wasn’t even planning on replacing the melted truck liner. A few more days later and my BP calls me and says my wife was out of line. I told him it looks really bad on him that he knowingly let an employee drive the company truck drunk to which he respond “I never went outside to watch the fireworks” and of course I don’t believe him. He’s also completely opposed to the idea of any sort of punishment or write up and was actually mad about that idea.

What I’m hoping I can get out of this is my business partners complete removal from the company (this isn’t the first time he’s been a liability) we created without any monetary compensation or assets. We don’t have a partnership agreement but we do have documents stating the company is a 50/50 ownership we’ve signed. Is there any grounds for this even if it’s true he didn’t know he drove the company truck? What would you do next if you were me?