I just think he was the kind of guy that wanted to believe the best about people.
He may have had a niggling fear that Jodi might do something at the next level of crazy, but like most of us, he probably didn't REALLY think it would go there.
True story: 20+ years ago when Mr. Knot and I were dating (the first time around-we broke up and reunited and got married two years ago, lol), I was at his apartment one night, ya know, nekkid, and we heard this loud sound from the living room.
Turns out it was his ex gf, prying open the window with a tire iron! She was halfway in the window when the future Mr. Knot went to check and she ran to the kitchen, grabbed a knife and tried to lunge at him, and then at me, cowered under the covers.
He was able to calm her down, she left, and neither of us ever thought about calling police. Mostly because we felt kind of sorry for her and knew she was a "little off". And we knew she didn't take well the breakup which happened many months prior. And we were really young and naive and I didn't read WS back then!!!
All that to say, Travis may have felt some responsibility, whether right or wrong, for her cray cray and maybe he just thought with time she would stop it.