<human>: Hi LegalAdvice!

My friend regularly visits and sometimes spends the night (~1-2 times per month).  They have a service animal (small dog) that comes with them when they visit and stay over.

I'm a subletter in an old (rent-controlled) apt building in San Francisco.  The building mgr has never given me any trouble about the dog, but I've never run into him when the dog was around.

Recently they wanted to do maintenance in the apt and gave 24 hour notice.  One day was listed on the notice. They showed up the next day to finish the work and it wasn't a convenient day (they were painting the entryway and it was my day off - I couldn't get in/out of the apartment all day if they started). I asked them to come back, and they said they gave notice. I said yes, you did, for yesterday. If you needed more access you needed to put all of the dates or date range on the notice. After a lot of back of forth and calling the master tenant, they begrudgingly rescheduled the painting for the next week. 

Within 20 minutes I get a notice under the door that they have witnessed a tenant from our apt with a dog in the building last month, and this is a pet free building and that's a violation of the lease. It's not technically a pet free building as many tenants (including our master tenant) have/had cats (not sure that matters).  I think the notice was retribution because they were upset about rescheduling the painting.

I'd like to be able to have my friend visit, but they have to have their dog with them at all times. I would think there's some rule that service animals are allowed to come with visitors, or am I mistaken? If so, how should I handle this with the building manager? He's really off his rocker and has harassed tenants when he has a bone to pick with them, so I'd like to make this quietly go away but still have my friend visit if possible.

Thanks :)

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: Building manager gave notice of lease violation due to friend visiting with service dog - are service animals exempt from "no dog" lease provisions and if so how do I handle the situation?