rnzoli,
This video might not have raised FullWings' eyebrows, but it certainly got my attention!
Although I'm a helicopter pilot, basic mountain flying technique holds true regardless of the machine you're flying so hopefully you don't mind some feedback from a rotary wing driver who spends his time in the mountains of western Canada.
When approaching a ridge line like this, I'd always recommend losing altitude to below the ceiling/cloud bases well before reaching the mountain - you improve forward visibility and avoid avoid entering cloud like you did approaching the mountain side. It's hard to know what the clouds are doing behind the 'wispy' parts you were scud running - as it happens on this occasion they disappated but they could have equally worsened and I suspect this would have then have had a different outcome.
In questionable visibility you should fly an approach other than 90 degrees to the ridge line - typically 45 degrees is advocated. Flying offset/parallel to the ridge gives a number of advantages: you have time to look at the topography of the ridge, you can better judge visibility, you can 'feel' the wind and you have a shorter turning circle to carry out if you don't like what you see or there is an emergency. I'm not sure what your IAS was but even at a modest 100mph you don't have too long to make decisions and action them when flying directly at cloud +/- mountain.
In this case there was a clearer bright area with lower ground to your right - this would have been my choice of area to attempt a crossing, especially as there was falling ground to use as an escape route. Always leave yourself an 'out' for as long as possible and only commit to the crossing when you're sure that what lies beyond the ridge is VFR.
As RatherBeFlying mentioned the wind was upslope as you approached and you got on the 'backside' after crossing - in stronger wind conditions you can expect rotor action and down drafts after crossing the demarcation line, so you'd be wise to increase your crossing altitude if the cloud base allows for it. I'd also be cautious about relying on forecast wind speeds around mountains - they often generate their own unique weather and winds can be significantly stronger (or lighter) than anticipated.