Certainly, this "slip back to synch" will be much faster and
    completely reliable if you transmit two stop bits and look for only one
    so if speed is not critical, that is recommended.  But it's not actually
    necessary on a decent link.

I don't see how you can resynchronize accurately without a mark condition
lasting more than one CHARACTER time.  Otherwise, there's no way to
distinguish the stop/start bit combination from any other two consecutive
zero ("space") bits.

BillW