Not technically head-hopping, but I stopped reading. It was like jumping from one character's head to another.
I've seen similar things done to great effect (but one chapter per character), and at other times hated it.
I do not think the technique is a problem, per se, I think the problems stem from why the author chose to do it.
I will be a DEVIL'S ADVOCATE here. I think there exists an orthodoxy of views here that is misleading, if not totally wrong. I'm sure I'm not alone in thinking that, or at least in having doubts.
Hoping to prompt a debate, I will play the heretic, and express views I do not necessarily (totally) agree with. Not knowing how to explain these things rationally, I will be using over-the-top offensive language.
I think many of you here are a bunch of POV-Nazis.
You're all so bloody adamant that 'authors must have artistic freedom to break any "rule"' when it comes to punctuation and grammar.
But NOT when it comes to the restrictions that apply to whose thoughts may be shown when using various POVs. You constantly bleat those rules must never be broken. [May Tolkein forgive me,] you think this is The Rule that rules over all other rules.
It seems to stem from the doctrine that 'readers identify more with characters when 1-POV is used.' This is COMPLETE NONSENSE. Readers identify just as much with well-crafted characters when 3-POV used, and there is centuries of evidence proving that is so.
There are valid reasons for choosing 1-POV, the main one being to control when and how information becomes available to the reader. When 1-POV is used readers understand they will not know information until the MC learns it.
'Head-hopping' is NOT a mortal sin, but it does have it's dangers.
There is no inherent reason why thoughts of ANY characters should not be shown, and not just their actions and words.
The main danger is showing too much information. But the solution is not some arbitrary restrictions on whose thoughts may be shown, for example never showing the thoughts of two different characters in one scene.
A reasonable solution is to advise authors to be very cautious of showing thoughts by ALL characters at ALL times.
I think more appropriate advice is before showing any thoughts, authors should ask themselves: (a) Is it essential readers know this? Now?, and (b) Is there a reason other characters should not know this? If they have no satisfactory answers to those questions my guess is showing the thought would usually be "telling", and authors should consider how (and whether) to show the idea instead.
... removing my forked tongue from cheek now ...
My sincere advice to newer authors is never choose 1-POV without a clear plan for the ending of the story, and then assessing that 1-POV will work. If you do that, you may find 1-POV imposing obstacles to showing where the plot leads you that would not exist if you'd written the story in 3-POV.