From experience, I have found some O.T.'s in my county (Herefordshire) sadly appear to be employed to save the council money, rather that inform anyone of what may be available to them and provide support.
In my opinion it sounds like they did not provide information about disability facility grants or minor adaptations, an O.T. should also assess the needs outside the home.
I believe you are entitled to a second opinion. Contact your local authority, if phoning also send a letter or email for confirmation, so you have a clear record, and ask for a second assessment by a different or independent O.T.
If your sons are disabled, they automatically have protected characteristics under The Equality Act 2010, so it may be seen as discrimination if an O.T. said your sons were not entitled to anything due to their disability.
Here is a link to the Equality Act 2010 Section on discrimination
and an easier to read version
Further, to quote from something I came across a while ago:
Local authorities have a general power under the Act to charge for
services they provide to meet needs. However, they are prohibited from charging for a service consisting of the provision of disability equipment and/or minor adaptations that assist with nursing at home or aid daily living.
A minor home adaptation is defined as one costing £1,000 or less in the charging regulations. These are often related to mobility and falls prevention, for example: a short concrete ramp or shallow steps, a grab rail or long or external metal hand rail, automatic lighting at the front access, or a door-release intercom system.
See section 4.1 for the charging rules for more major home adaptations.
Further reading here: http://www.ageuk.org.uk/Documents/EN-GB/Factsheets/FS42_Disability_equipment_and_home_adaptations_fcs.pdf?dtrk=true
Here are some other links, I hope you find them useful:
Please share the website and Facebook page detailing the inadequate care and support provided to a vulnerable autistic person, with everyone you know. Thank you.
http://www.whileincare.info/blog/ (contains photo evidence)