My dd aged 5 has a had a few pee accidents and a couple poo accidents.
Most of the pee accidents are not getting to toilet in time and the poo is she doesnt realise until its there.
I think she is too engrossed in what she is doing as most if not all accidents have happened at dgp or her df home.
Her dgp are thinking its probably psychological and signs of an happy child. 
dgm is a mega worrier. Lots of history of messed up upbringing and naturally distrustful.
Two times over this year dd has
Said that she doesn't like my dp as he shouts and swears at her..
And has recently said she doesn't like him when he sends her to her room and gets angry and makes her wait for food.
I know he doesnt swear at her he's to soft to do that but the rest I dont see a problem with other than she said she is scared.
How much of it is true as by all accounts she should be scared of me as I have more sterness and do all of the above except send her to her room.
I usually do the count to 123 and then consequences but never get passed 2.
Now dgp are worried that he is mistreating her and this is why possibly she is having accidents.
Also the other day she said to her df lets go kill that bird but im almost certain she meant bug. (Not that thats is any better)
To me they are separate as they are ignoring the fact she doesn't have accidents at mine And that I think they are reading too much into what she said.
We are not perfect but I dont think my dd is unhappy As her other behaviours are normal and nursery have no concerns she is a loving and confidendt child socially and at home.
Please be gentle.