Background: I'm very lucky and I have an office job that I can do from home (with occasional days in the office). I work part time, but have an informal agreement with my boss that I'll be available on my mobile most of the day - unless driving or at a pre-notified event such as toddler groups. I usually work from about 8.00 until 10.00, but this can vary; as it happens, I worked from 7.30 until 9.30 this morning.
So, I took the bin out to the wheelie bin today - DS playing happily in the living room with his toys. I heard the house phone ring but had my hands full with a lovely drippy bag so prioritised the bin. Most people have my mobile to contact me on anyway, so most of the house calls during the day are irritating sales calls.
Now, house phone normally has a key lock on it as DS (21mo) is inquisitive. As I came back in, DS handed me the phone - and I saw that he'd managed to answer it, so DH had obviously forgotten to lock it after using it last night. I said "hello, is there someone there" into the telephone, and found that it was my very irate managing director on the phone.
I was then lambasted for
a) not answering my phone
b) allowing my DS to answer it, and
c) why wasn't I supervising DS?
I was just so taken aback that I wasn't as diplomatic as I possibly should have been and pointed out that:
a) he should not have been calling my home phone - he must have looked up the phone book as it is not on my employee records.
b) that being the case, it's up to me who answers the phone, and
c) it's also up to me whether or not I'm in the room with my DS or not.
Oh and d) I've actually finished for the day anyway (managing director doesn't know about the informal agreement or he would take advantage).
I'm now a bit 
about the whole conversation. I know there is no reason for a disciplinary meeting, as I was polite, but not diplomatic IYSWIM, and he was technically in breach of my working agreement. However, I did answer his query.
But I'm now starting to doubt myself.
I'm not being unreasonable in choosing not to answer my home phone am I?