DDR3 and DDR3L are electrically compatible. DDR3L works fine in DDR3 devices and, indeed, tends to come off the same production line as DDR3 but simply passes the functional test at 1.35V.
As for the other way around, DDR3 SODIMMs on a Haswell-based motherboard should simply fail POST with a double beep. Both the memory and notebook will be OK: putting the right memory in will resolve the issue.