[51highland]

152 Brigade were lead brigade for the assault on Le Havre on the night of 10th/11th Sept 1944. 5th Camerons & 5th Seaforth being lead battalions. 2nd Seaforths were delayed due to lack of gapping in their assault area.. Some of the gapping equipment, i.e flails etc. did not arrive and of those that did, some were lost on mines. The bridge layers and Fascine carriers were failing in their attempt to make a crossing when the infantry should have been well into the defences.
After Le Havre, the divisional transport was taken away from 13th to 30th Sept. 2nd & 5th Seaforth went in Best, Holland 3rd October, 1944.

As suggested it is quite likely your man died of wounds.

I would personally write to the regimental Museum at Ardesier, as suggested by Owen, they have all the relevant histories on site. They have always been helpful to me.
sorry I do not have more info.