A employee goes off sick (signed off) with a strained Achilles tendon for 2 weeks

on their return to work 2weeks later claims industrial injury from pushing racks on the Friday morning
There has been contact with HR over the 2 weeks and nothing has been said.

investigation reveals

no entry in the first aid book or any notification of an injury or accident to any manager
there is no single cause and the I.P. Cannot tell what did it
Just that "I felt a strain which got worse over 3 days, but can't say what time it started or why?"
The IP starts work Friday morning, continues Saturday and Sunday and Monday
Goes to GP Tuesday gets signed off,

First we know of this is 2 weeks later
Employee is known to ride motorcycles in spare time
Company does not pay sick pay other than ssp

There is no evidence other than their word that this is an industrial accident.......

If this was your site - would you record this as a RIDDOR accident or is it Ill Health?

Ian, I think we have all been faced with the same from time to time, and there isn’t always much in the way of a straightforward answer. In fairness some people have ‘accidents’ at work, but either ‘soldier’ on (especially if there is no contractual sick pay) and subsequently either make the injury worse or just continue to cope with it until they can‘t anymore, or the injury genuinely doesn’t reveal itself until some time later.

I suggest that some of these are entirely genuine, while others may indeed be ’spurious’.

My approach has generally tended to be giving the benefit of the doubt unless I strongly feel otherwise. I make sure that the ’disparity’ between the reported date and claimed accident date is clearly evident, and I have even made reference to this in investigation and RIDDOR reports.