That is something I have always raised an eyebrow at. Jack was drinkin, sure enuff, and he was lying back, same as Ennis. Yet he was MUCH more sober-appearing then Ennis prior to FNIT, just as you point out Thomas... The scene where' guys like us march off to hell...'--when Ennis replies that he hasn't yet had the opportunity on his face, as Jack responds, well, Ennis has this half smirky knowing look. He all but gives Jack' That Look', the one which says I know where you're at, and look at the glances he gives Jack.....
. Jack symbolically hands him the apple in the Garden of Eden, in this case a bottle of whiskey. Ennis accepts, and Jack looks delighted, absolutely elated, go back and check out that brilliant & nodding 'yeahyeahyeah okIGOTIT, cowboy!' smile on the DVD.
It's as if Jack knew--which he may have--and stayed sober, allowing Ennis to get completely sh*tfaced drunk. He understood EDM well enough by then to know in his gut that Ennis needed a shove and something to reduce his fear. Because --and you pointed this out--when he handed EDM that blanket he looked very sober. And he sounded dashed when Ennis said he would curl up by the fire. Jack may have simply had enough and said to hell with this, time to make that move.
You have me thinking here dude.....I always thought Jack was simply responding to Ennis' admission that he hadn't much experience, hadn't had the opportunity. But now, well what do you think on this??
Jack