During my league game earlier the opponent made 14 substitutions of the number 3 using all different players literally every time the ball went dead. Made no difference to me I think but as it was literally every time play stopped it surely has to be a bug?

It also shows on the post match summary that the #3 got injured after 5 minutes, but was substituted for the injury on 3 minutes

Short of having a Dolorian go 88mph I'm not sure how that one works

Thanks for your feedback, we will fix the bug.

I had the same issue, the number 8 was swapped 17 time (once was an injury) and then in the friednly rematch he was swapped 15 times.

A bit annoying as it was a close game and against a top of the table rival so could prove costly to my other side (Shaw RFC).

Just a mail back saying these were swaps of players on the field.

That's not correct, there are two injury subs:

Wilson is injured and replaced with Steven - so off the pitch @ 6 min
Ronald is injured and replaced with Karl - so off the pitch @ 25 min

The issue is around swapping the no8s Wilson & Steven. There are no other players in his side with those names, so no-one else is leaving the pitch.
As follows:

19 min; Steven on - Wilson off the pitch
25 min; Wilson on - Steven off the pitch
28 min; Steven on - Wilson off the pitch
33 min: Wilson on - Steven off the pitch
36 min; Steven on - Wilson off the pitch
46 min; Wilson on - Steven off the pitch
49 min; Steven on - Wilson off the pitch
53 min; Wilson on - Steven off the pitch
56 min; Steven on - Wilson off the pitch
60 min; Wilson on - Steven off the pitch
66 min; Steven on - Wilson off the pitch
73 min; Wilson on - Steven off the pitch
81 min; Steven on - Wilson off the pitch

At no point are both of these on the pitch at the same time, so positional swaps. A player leaving the pitch is surely a substituion, if seems quite clea that the player was swapped, healed, and then sent back on. The same pattern is seen in the following friendly game.

I don't think it unreasonable for the result to be discounted as they are clearly exploiting a bug.