I dont know tbh if it is possible to recreate as I've been trying for a while

this makes a sub 4:30 run possible .

Yeah I had this happen once as well - I already have it listed on the strats post! If it can be made consistent, sub 4:30 can happen sooner or later!

Any idea of how or why did It happen?

Seems like it happened in a similar way here in the video as with me: the broom sweep happened like exactly in the middle. Might have something to do with the placement of the broom?