Cirrus SF50 pilot reported a conflict during takeoff from an airport which had closed its Tower. Reportedly; another aircraft taxied across their takeoff runway midfield after they were about 50 feet in the air.

Narrative

I was departing out of ZZZ airport around XA00 on Day 0. The field is normally Class D but the Tower was closed so it reverted to Class E and we communicate on CTAF. This was after a sporting event so there was considerable more traffic departing late at night out of the now Class E airport. Winds were something like 310 at 6 knots and the active was Runway XX. As I taxied out; I noted there was a larger Jet sitting down at the end of Runway XY and I wasn't hearing him make radio calls. I continued my taxi to Runway XX; held short and called approach to get my release for departure. They released me for departure and gave me a 5 minute window to be airborne. At this point the jet that had been holding short of XY taxied across the runway and began taxing down towards Runway XX. After he was clear; I took Runway XX and began my take off roll. As I rotated and was about 50 feet in the air; I saw the jet taxi out onto Runway XX to cross it around mid-field and I passed over him about 100 feet I'd guess. I never heard him make any radio calls. I confirmed multiple times that I was on the correct frequency and radio on my airplane. I even called the FBO when I landed to confirm I had the correct frequency.