I would say it is going to depend on the setup.
If you hard plumb into the home's sewer line and the line is sealed and pressurized, it will offer back pressure to the pump to slow the flow rate and force water through the drain system at higher pressure at pretty much any flow rate. Although if the pressure is high enough it could force water out of the home's drains.
On the other hand, if there is a small section of hard plumbed pipe that empties into a non-sealed open pipe such as a french drain, this drain system will gravity drain and as such have a limited flow rate through the drain pipe depending on the elevation change so it could easily overflow.
If the backwash pipe empties into lawn or a catch basin and then is allowed to gravity drain from there at it's own rate, there is no issue.