British police have never said the Skripals went out for the whole day, and there’s good evidence to suggest they did in fact return home in the afternoon. Within a fortnight of the incident, CCTV footage emerged showing Sergei’s maroon BMW very close to his home.
Recurring pro-Kremlin disinformation on Salisbury attack. euvsdisinfo.eu/disinformation-cases/?text=skripal&disinfo_issue=&date= Many competing and contradictory stories promulgated by Russian state-controlled media on the Skripal poisoning https://euvsdisinfo.eu/disinformation-cases/?text=sergei+skripal&disinfo_issue=&date=
On Sunday 4 March Sergei and Yulia Skripal were poisoned in Salisbury with a military-grade nerve agent of a type developed by Russia. As for the scar on her throat, news outlets, including the BBC and Telegraph, have described it as a result of a tracheotomy, a surgical procedure which opens a hole in a person's windpipe to help them breathe. She has not shared specifics of her treatment, but described it as "invasive, painful, and depressing." http://uk.businessinsider.com/skripal-poisoning-yulia-skripal-neck-scar-hints-at-painful-recovery-2018-5?r=US&IR=T
For the UK response see: https://www.gov.uk/government/news/novichok-nerve-agent-use-in-salisbury-uk-government-response
The OPCW have confirmed the UK findings in the case. "The results of the analysis by the OPCW designated laboratories of environmental and biomedical samples collected by the OPCW team confirm the findings of the United Kingdom relating to the identity of the toxic chemical that was used in Salisbury and severely injured three people." https://www.opcw.org/news/article/opcw-issues-report-on-technical-assistance-requested-by-the-united-kingdom/