Obviously I don't have expertise in 'sniper drone' technology or munitions, but I can quite clearly see that Prof Mamode's specific reference was out of step with everyone else. Whereas other doctors and experts reported that the distinctive cuboid fragmentations were dispersed from a larger shell (which may have been dropped by a drone), indiscriminately injuring over a large area, Prof Mamode suggested that the cuboid fragmentations were 'bullets' fired from [a gun attached to] a sniper drone in precise targeting. I think he has simply misremembered something he has read/heard on that specific point rather than demonstrating expertise.
Looking at his testimony as a whole, Prof Mamode makes a number of references to things he has read/heard, e.g. 'a paper in The Lancet... it was reported in Haaretz... He also makes several, somewhat inflammatory claims, e.g. 'to my mind it cannot be anything other than collective punishment. It is just a consistent attempt to essentially wipe out a large part of the population.'
surgeons also not renowned for crying easily, you can see in his testimony how disturbed he was by what he saw
I don't think anyone is disputing that some of the injuries are horrific, but as you point out, surgeons are not renowned for crying, and we can only compare Prof Mamode to other surgeons who have volunteered during the conflict. His experience in Gaza is not unique but his reaction to that experience is - everyone is different. Just before he broke down at the committee hearing he said; 'So you have this constant whine, which is psychologically very affecting because it represents danger and is constantly there...'
Something else I have found that may be relevant to his distress (compared to the other surgeons) is this lengthy dispute with his previous employer/s - reported in the Daily Mail shortly before his time in Gaza;
July 2024
An internationally recognised senior surgeon ... has successfully sued the NHS after he was pushed out when he raised concerns about patient safety.
Nizam Mamode was subjected to an 18 month suspension from paediatric duties after his complaints led to a review which saw the surgeon face allegations of 'widespread bullying and intimidation'... [which he denied]
As a result of his exclusion, the surgeon suffered 'extreme anxiety and depression' and quit his job.
The remedy/compensation hearing was provisionally fixed for September 2024, so still not fully resolved when he was volunteering in Gaza, mid-August to mid-September 2024;
https://www.dailymail.co.uk/news/article-13648241/transplant-surgeon-Crown-sues-NHS-patient-safety-concerns.html