Thank you for your comment and sharing that story.

Time travel violating the conservation of energy is a commonly debated topic. There are two potential lines of thinking around this:

1. A point in the the present, and a point in the future are part of the same “system” (space-time is a single fabric -it just so happens that humans experience the “arrow of time”). Thus it follows that moving energy across these points in time is fine because the amount of energy across the system remains the same.
2. The big bang showed us that something can come out of nothing. This too does not necessarily breach the first law of thermodynamics