as long as conditions at his departure point were still legal for VFR yes, he could return.... OR...
He could have chosen any number of airports in that area to land and wait for conditions to improve... each of those 'alternate' areas also legal for VFR. All of this with help from Air Traffic Control.
As for 'navigating thru' the weather.... it sure looks to me like he did NOT make this attempt... rather, he turned to avoid worsening conditions... but he was too late. Of course, what is being 'reported' at this time... altitude, direction, direction at impact, are ALL speculative right now. This next is rather techie... so may or may not interest you.
The Altitude he was flying at is mystifying at best. He reported at 1,400' over Hwy 118... impact was in a box canyon... 1,400' is not enough altitude to get IN to the canyon unless entering from near the mouth of the canyon.. impact was at slightly under 1,100'. And to enter the canyon at 1,400' feet would require a left hand turn... which would then indicate the pilot was seeking to reverse course and avoid the fog bank. - JamesJM
