I think a lot of people will be making the assumption that the present Government are starting to lose their grip of military affairs anyway, and an apology will simply exemplify that.
I'm afraid if it's not health or education it doesn't get a look in in government priorities. There are no votes in guns (nor ships nor aircraft) therefore politicians are quite happy to leave defence matters on the back burner until something like this comes up and bites them.
Re a petition,
L.J. not a day goes by without several of these appearing on Facebook. I doubt if any of them have ever had any affect on government policy, even those which reach the magic number, whatever it is, which guarantees them discussion in the Commons. A waste of ink (or pixels!).