This occured also in my Philips ML 160W from 2005 in the last years. But more common in this lamp.
When my HWL lamp hot restrike after several seconds of negative glows it restrike smooth, without any flickering (Unlike most SBMV of several LG members). You can see this hot restrike
here (Move to 4:25).
Sometimes it even strikes suddenly from nothing, without the negative glow first, like the penning start HPS lamps.
Why this is happening.