sounds about as false positive to me as they come.
the tool description says it embeds xdelta.exe into itself and extracts it on-demand for being used.
xdelta itself is notoriously known for tripping false positives because of the way it works (it reads and modifies other files, so heuristics automatically think its EVIL!!!!11one)
that said, i havent used this particular program myself so im not going to swear on it being absolutely safe, but with patchers this kinda thing happens dime a dozen...
I'eve even written one myself that instantly dissappeared when i compiled it because (out of all things) windows defender decided that the result of my source code once compiled is harmful. lmao.