Scam?

This afternoon, I was driving into a carpark at Bukit Merah, while I was queueing to get in, I noticed a couple standing in the centre of the entrance, together with an old lady on a wheelchair. When it's my turn to go into the carpark, the man blocked my way with the old lady on the wheelchair and the woman spoke to me.

The conversation:

Woman: Miss, can you help this old lady (pointing to old lady on wheelchair)? We are her neighbours and we brought her here to see HDB regarding her house (shows me HDB documents). She very poor thing, she has problems with her house and has lots of unpaid bills, and now she had no money to go home. She stays in Clementi. Can you spare her $10 to take a taxi home?

I looked at the old lady, and I thought I saw her turn away in embarrassment.

Me: (open my purse and saw no small notes) sorry, but I don't have any small change.

Woman: Please, can you help her? (showed me another stack of HDB bills). We are her neighbours and we brought her here to see HDB. We staying in Pasir Ris, brought her all the way here leh.

Wait a minute. The woman said she lives in Pasir Ris and the old lady lives in Clementi but they are neighbours?? And I thought HDB shifted to Toa Payoh?

Me: Since you already helped her so much, why can't you give her another $10 for the taxi ride?

Woman: We already helped her with a lot of our savings. And I'm not working now, was retrenched recently.

Me: Sorry, I really want to help, but I've got no small change.

I drove away.

In fact, I wanted to offer sending the old lady home. But when I parked my car, the couple and the old lady was gone. Maybe to find other good samatarians for help. Initially, I thought that the couple wanted a free ride but they actually asked for money.

But the more I thought about it, the more I found it fishy. Firstly, the old lady should be going to either the HDB at Clementi, where she lives or the the HDB Hub at Toa Payoh right? Second, the couple look like they can afford $10 but they chose to ask for it? And third, how come they can come all the way from Pasir Ris to Bukit Merah but can't go the extra mile of sending the old lady to Clementi, and instead, chose to ask for money for the taxi ride?

I should have offered the ride and see how the couple react. If this is a scam, I pity the old lady, for being used by the couple.