I'm used to seeing a lot of 'image without alt text' warnings. It now seems almost normal, despite the fact that it's a HTML validation error as well as an SEO black mark. It's a quick win, why are we so lax?
In this case there are many other html warnings; missing closing divs, p within h3, closing p with open span. (There are a lot of warnings, just a small section is shown in the screenshot below.)
The SEO results showed up 'missing title' on many important pages. This was hard to believe and indeed it shouldn't be believed - the title tags are present. However (I might call this a bug in Scrutiny) some pages seem to have multiple <head> sections, some even nested!
This unexpected issue tricks Scrutiny into 'body' mode rather than 'head' mode, and it's likely to miss other meta data and <link> tags. I will see that Scrutiny gets an update so that it handles this situation properly - correctly reports the multiple <head> tags and doesn't miss the titles.
Another important issue is links to insecure http:// pages from secure https:// pages - including an http version of the contact form.