1) There was a disruption early on in their test. Should I push for this to be mentioned in the head teacher's report?
Yes, but schools may be reluctant to comment in writing! If so, you may need to follow up with a letter or email expressing concern.
You can then use a copy of your letter or email as evidence for the review/appeal.
You can also ask for a copy of the invigilator's log, provided names are redacted.
2) Also, DS's strongest subject is probably maths, yet this was his weakest score. Do we need to find an explanation for this?
Not necessarily (although if you have a good reason, you will of course use it.). It could down to the fact that no test is 100% reliable in every case.
The important thing would be to have plenty of evidence of very high ability in maths.
I wrote in another thread about a Kent parent who set out to prove at appeal that the 11+ maths result was a blip. He had the results of a series of CATs tests, taken over an extended period, where quantitative reasoning came out at the 99th, 98th, 98th and 95th percentile. Even allowing for confidence intervals, the sheer consistency of these excellent results made for a compelling academic case.
There was also very strong support from the school. “X recently sat a year 6 maths SATs paper and achieved a 5B. X is consistently good at tests. ….. X is in our top set for maths
Is there anything else I need to push for while I'm trying to be tough?!
If your son was a '2', it would be useful to know how many of the school's 2:1 and 2:2 recommendations were successful in the 11+. Some schools are reluctant to divulge this information, but it will eventually be available to all those going to appeal (provided they asked for the review paperwork to be completed).
Finally, thanks to everyone that contributes to this site for their help and expertise. We would never have got to this stage without it.