I'm thinking this photo is most likely a joke or, perhaps, a frat prank, or he enjoys being made helpless. I can't think of any medical team that would permit a patient in a full body cast to leave the hospital - unless, of course, he had 24-hour care available. It reminded me of the old joke: A straight guy visits his straight friend in the hospital who has both arms in traction. Lying there with a very obvious hard-on, he asks his friend to lend him a hand to relieve his boner. The visitor closes the privacy curtain, dons face mask, hospital gown, and two pair of latex gloves, and with trepidation wraps a hand around his friend's dick and begins to whack him off, whispering, "If you ever tell anyone, I'll deny it and you'll be a dead man!"
And, once his body recovered enough from the injuries, his cock would begin to show signs of life again. Would you offer to jack him off so he'd avoid a serious case of blue balls?
If you wouldn't make the offer, if he asked you to do it - to get his rocks off - would you?
Guys whack cock together all the time - sexual orientation doesn't matter. And it shouldn't. The jack off group I belonged to (until it folded due to a lack of venue) 90% of the members self-identified as straight and most were married. The guys in the military circle jerks I attended on Friday nights in the barracks - straight (well, at that time you couldn't admit to being gay - but damn near every one of them eventually married). It's a bond between men - something guys have in common. We should be able to admit we enjoy the activity and we should be able to enjoy it together without negative connotations of any kind.