I am aware of what the form says, I have helped people before with staying in the UK.
What the solicitor was alluding to is this section in the application form:
6.14 Have you engaged in any other activities that might indicate that you may not be considered a person of good character?
The fact that he is under suspicion of drug driving (and therefore taking drugs) could come under that category. There is also the possibility that when police checks are done for the visa, it will throw up the arrest on the database. (They do not just report convictions) and non disclosure could be held against him.
There is also the issue that even if he gets a visa, he should report any changes in his circumstances, which the conviction (if it happens) would be. The authorities would then be aware that he was under investigation when he applied for the visa and this would count against him.
“ Report all other changes
Fill in the change of circumstances form to report any other changes of circumstances including:
your contact details
your legal representative’s details
dependent family members’ details
if you separate from your partner
if you get a criminal conviction
if any of your children stop living with you”
From the .gov website:
Report a change of address, personal details or circumstances if you have a visa or biometric residence permit (BRP), or if you've applied for one
www.gov.uk
My main concern was that the poster committed himself to large payments for a university course that he may not be able to finish, so if he is seeking work that does not apply, but even so he should seek legal advice before completing the application form in his circumstances.