So in general I am an outgoing person and tend to meet a lot of new people. 
My work is in a software company and some of the people I meet are software engineers. I am a senior engineer and architect and currently run a team in the company.

Our company like most software company's is most definitely short on good engineers and the other day on the train I met two young people in the last few months of university who were very interested in looking for work. We are specifically looking for this profile and I know it. They asked me for my card and sent in a CV the next day.

I forwarded it to HR saying something like "I was waiting for the train and met some engineers here is their resume . . . is this interesting for you?" 

I got this message back from HR and am debating on what to think about it:
"What a nice place to recruit new people =)"

I have a feeling this is a passive aggressive note like I should feel bad about promoting the company. In general I am planning to ignore the comment (at least not respond by email) but it makes me wonder how should I interpret this and if I should do something differently? 

The two people I met in my mind have excellent profiles, looking at the one CV its very solid and maybe I am too open minded but is it reasonable to consider them or is it a black mark on me or the candidate just because I met them in a two minute conversation while switching trains instead of a two minute conversation on a recruitment day? Why would this be worse than applying via our public website?