Personally I have a bit of a different take on it, I don't believe it's the clients responsibility to manage time, the responsiblity should rely on the shoulders of the service professional. I think this is something that isn't unique to this industry either, when I deal with an accountant, a lawyer, anyone that is providing billable hours it's up to them to let me know in advance what I will be billed and to manage their time accordingly.
The smaller the account the larger the burden is to stick to the timeline as provided, eg. if I go to a personal tax advisor and am looking at getting my taxes done they will tell me it's only $200 to file. Now in the middle of it they realize they misquoted because I have several expenditures that I had not previously explained and they will need to file several different forms on my behalf requiring additional time making the total cost $350. This is a substantial change in cost and I would expect them to approach me before moving forward with this or I might not pay the additional fees as I had not previously agreed to them.
If I approached the same tax accountant with an RFP for my large multi-national corporation which needs it's taxes filed I would expect it would require a team and many hours of work. Lets assume the proposal comes in at $100k in billable hours for his team (I like round numbers). Now as a large project goes on it's only natural that some overtime is going to happen at 'crunch time' but one would expect they would not come to the me the client for approval on each billable hour as that would be poor customer service "excuse me sir, do you approve this $400 additional on your 100k project?"
but rather they would only burden the client at a certain level or %. Otherwise if the account was important enough and they wanted the ongoing business they would compare the costs and look at where they made the error in the proposal process and consider whether they should comp the additional service or not.
In regards to the specific issue at hand, I will not speak to it. I wasn't there, I didn't see the communications and I don't know the details as none of us do. There are so many variables at play in these types of situations we really can't know what is best and each situation needs to be looked at individually.
If the situation were to happen to me what would I do?
Well it has happened many a time and each time I've handled it differently.
Clients that I enjoy and want to see again I simply thank for spending so much time with me and tell them that I appreciated them wanting to spend that time with me and then walk out.
Clients that I think were 'angling' for additional time when I had
clearly communicated the parameters I will let them know that their behaviour was unprofessional and that I will follow up with an email on how they can make the payment to make right on their debt. The key to this is that I am very clear that I communicate when one agrees to go 'overtime' since my date packages are flexible anyway it's a big difference so not hard to misconstrue (one doesn't book 6 hours and accidentally get 12
).
Clients where I think I made an honest mistake and I didn't communicate clearly enough for them, I chalk it up to my mistake and simply walk out. It's the cost of doing business and asking them for the money is just going to put them in an awkward situation. Instead I'm not out any overhead, just a bit of time which I can spare and in the end I've invested in a bit of goodwill and relationship building which goes a long way anyway. Next time I can manage my time better and they will understand and just like the person that writes the proposal and needs to look at where they went wrong I need to look at my process and see if there was something I didn't allow enough time for, perhaps I need to change the 2hour min. to a 3 hour min. or need to ask him to shower before I arrive, something to save a little time.